Water-based hot melt adhesive and water-based hot melt adhesive coating non-woven fabric thereof

Abstract

The invention provides a water-based hot melt adhesive and a water-based hot melt adhesive coating non-woven fabric thereof. The water-based hot melt adhesive comprises the following components in parts by weight: 100 parts of water-based polyolefin resin; 45 parts by weight to 85 parts by weight of powder wax; and 25 to 85 parts by weight of a powder tackifier; wherein the total weight of the powder of the water-based hot melt adhesive accounts for 45wt%-60wt% of the total weight of the water-based hot melt adhesive. A coating formed by the water-based hot melt adhesive on a medical packaging base material has good air permeability, and has reliable sealing strength and peelability after being sealed with a flexible sheet or a blister container at the periphery.

Description

Technical Field

[0001] The invention relates to a water-based hot melt adhesive, which can be used for a hot melt adhesive coating of medical product packaging to be suitable for heat sealing and achieve good sealing strength without affecting the air permeability required as a medical product packaging material. Background Art

[0002] The main purpose of medical supply packaging materials is to provide a sterile environment for medical supplies during transportation or before use after they are manufactured, so that the medical devices remain sterile before use. Medical supplies are generally sterilized after packaging, and the sterilization process can usually be divided into steam sterilization (SteamSterilization), EO sterilization (Ethylene Oxide Sterilization) and radiation sterilization (RadiationSterilization). In response to different sterilization methods, the medical packaging materials used are also different. For example, for packaging materials used for EO sterilization and steam sterilization, the material needs to have excellent gas permeability to ensure that water vapor or EO gas can effectively pass through the packaging bag during the sterilization process and sterilize the internal medical devices. In the prior art, the most widely used materials that have both good microbial barrier effects and air permeability can be medical paper or a polyethylene film with pores made by melt-blowing, such as DuPont

[0003] Such medical packaging materials are usually packaged by heat sealing, where a breathable material such as medical paper or a porous polyethylene film is heat-sealed on four sides with another plastic film or a blister. In addition to good breathability, the medical packaging material must also have good heat-sealing strength and peelability. Insufficient heat-sealing strength will result in poor sealing of the medical packaging, which may cause bag breakage due to high gas pressure during sterilization, while excessive heat-sealing strength will make it difficult for users to tear open the package or cause dust to adhere to the medical supplies due to pulling the fibers when tearing.

[0004] Such breathable materials for medical use, such as medical paper or polyethylene films with pores, are usually coated with heat-seal adhesives to be heat-sealed and packaged with various plastic packaging trays or films.

[0005] The heat-sealing adhesive used in medical breathable materials is hot melt adhesive for sealing. The traditional hot melt adhesive formula is to melt and mix the thermoplastic resin, tackifier, wax, filler, plasticizer, antioxidant and additives, and then shape them into the form of granules, strips, sheets and films, and then use hot pressing or hot melting treatment for processing.

[0006] For example, CN108587521A discloses a water-based coating heat seal adhesive for medical dialysis paper, which is prepared by stirring and emulsifying thermoplastic resin, resin tackifier, wax, emulsifier and auxiliary agent at 120°C to form a hot melt adhesive coating liquid, and is applied to medical paper or non-woven fabric to form a heat seal layer. This sealing layer provides high adhesion, but if the adhesion is too large, it is easy to cause damage when the medical packaging is torn, which may cause the medical packaging material to fall and pollute the medical material. In the medical blister box heat seal material disclosed in CN110591602A, the surface glue and the bottom glue of different components are coated, and the bonding force between the surface glue and the bottom glue is lower than that between the surface glue and the packaging material, so as to maintain the bonding force between the medical sealing material and the blister box but not easy to tear the heat seal material. However, this requires the coating of two layers of glue, which will increase the inconvenience of production. In addition, CN108441149A discloses a two-stage manufacturing method for preparing a hot melt adhesive coating for use in the heat-sealing layer of medical packaging materials. The manufacturing method melts and mixes a thermoplastic resin, a resin tackifier, and a wax at a high temperature above 160°C to form a hot melt adhesive powder, and then emulsifies and disperses the hot melt adhesive powder in a polyacrylic acid emulsion with an emulsifier to form a coating. This two-stage manufacturing method increases the complexity of production.

[0007] The present invention provides a water-based hot melt adhesive that can be used for medical packaging materials. The coating formed on the medical packaging substrate can provide good air permeability and has reliable sealing strength and peelability after being sealed with a flexible sheet or a blister container at the periphery. Summary of the invention

[0008] The present invention provides a water-based hot melt adhesive for medical packaging materials, which can form a coating on an olefin-based spunbonded non-woven fabric for medical use, so that the non-woven fabric still has good air permeability after being sealed with a flexible sheet or a blister container at the periphery, so as to facilitate steam sterilization and EO gas sterilization processes and maintain sealing stability, and at the same time has reliable sealing strength and peelability, so that when peeling the heat-sealed seal, the water-based hot melt adhesive interface can be stably disconnected and the pollution caused by the shedding of non-woven fabric substrate fibers can be reduced. Furthermore, the water-based hot melt adhesive of the present invention can eliminate the mixing step required by traditional hot melt adhesives, and after application, it can achieve the sealing strength and specific air permeability required for medical packaging materials.

[0009] The water-based hot melt adhesive disclosed in the present invention comprises 100 parts by weight of water-based polyolefin resin, 40 to 85 parts by weight of powder wax and 25 to 85 parts by weight of powder tackifier, and the total amount of powder in the water-based hot melt adhesive accounts for between 45wt% and 60wt% of the total weight of the water-based hot melt adhesive.

[0010] The water-based hot melt adhesive disclosed in the present invention preferably comprises 100 parts by weight of a water-based polyolefin resin, 45 to 80 parts by weight of a powder wax and 30 to 80 parts by weight of a powder tackifier, wherein the total amount of powder in the water-based hot melt adhesive accounts for between 48wt% and 57wt% of the total weight of the hot melt adhesive.

[0011] In the water-based hot melt adhesive disclosed in the present invention, the weight ratio of the powder wax to the powder tackifier is between 0.6:1 and 3:1.

[0012] In the water-based hot melt adhesive disclosed in the present invention, the glass transition temperature (Tg) of the water-based polyolefin resin is less than 0°C and the melting point is higher than 90°C, the glass transition temperature (Tg) of the powder wax is less than 0°C and the melting point is between 70°C and 180°C, and the glass transition temperature (Tg) of the powder tackifier is greater than 0°C and the melting point is between 90°C and 160°C.

[0013] The glass transition temperature (Tg) of the water-based hot melt adhesive disclosed in the present invention is between -120°C and -50°C.

[0014] In the water-based hot melt adhesive disclosed in the present invention, the particle size (D50) of the powder wax is between 3 micrometers (μm) and 20 micrometers (μm), preferably between 3 micrometers (μm) and 15 micrometers (μm).

[0015] In the water-based hot melt adhesive disclosed in the present invention, the glass transition temperature (Tg) of the powder wax is less than 0° C. and the melting point is between 70° C. and 180° C. In the water-based hot melt adhesive disclosed in the present invention, the powder wax can be, for example, a group consisting of Fischer-Tropsch synthesis powder wax, polypropylene powder wax, polyethylene powder wax, oxidized polyethylene powder wax, microcrystalline wax and combinations thereof.

[0016] In the water-based hot melt adhesive disclosed in the present invention, the particle size (D50) of the powder tackifier is between 3 micrometers (μm) and 35 micrometers (μm), preferably between 5 micrometers (μm) and 30 micrometers (μm).

[0017] In the water-based hot melt adhesive disclosed in the present invention, the powder tackifier is a group consisting of C5 petroleum resin powder, C9 petroleum resin powder, C5 / C9 copolymerized petroleum resin powder, hydrogenated C9 petroleum resin powder and a combination thereof.

[0018] In the water-based hot melt adhesive disclosed in the present invention, the water-based polyolefin resin can be, for example, a group consisting of water-based polyethylene resin, water-based polypropylene resin, water-based polybutylene resin, water-based oxidized polyethylene resin and combinations thereof.

[0019] In another embodiment of the water-based hot melt adhesive of the present invention, the water-based hot melt adhesive may further include a water-based emulsion tackifier. In another embodiment of the water-based hot melt adhesive of the present invention, the water-based hot melt adhesive may include 10 to 60 parts by weight of the water-based emulsion tackifier per 100 parts by weight of the water-based polyolefin resin, and one or more emulsion tackifiers may be used.

[0020] In the water-based hot melt adhesive disclosed in the present invention, the water-based emulsion tackifier can be a group consisting of petroleum resin emulsion, rosin ester and its derivative emulsion, terpene resin and its modified resin emulsion, thermoplastic phenolic resin emulsion, low molecular weight polystyrene emulsion, ethylene acrylic acid copolymer emulsion and combinations thereof.

[0021] The present invention further provides a water-based hot melt adhesive coated nonwoven fabric, which comprises a polyolefin-based spunbond nonwoven fabric substrate and a coating formed by the water-based hot melt adhesive on at least one surface of the polyolefin-based spunbond nonwoven fabric substrate. The water-based hot melt adhesive coated nonwoven fabric has an air permeability of less than 180 seconds and a sealing strength of greater than 220 g / 15 mm.

[0022] The coating amount of the water-based hot melt adhesive of the water-based hot melt adhesive coated non-woven fabric of the present invention on the olefin-based spunbonded non-woven fabric substrate is 10 g / m 2 Up to 20g / m 2 between.

[0023] The above invention content is intended to provide a simplified summary of the present disclosure so that readers can have a basic understanding of the present disclosure. This invention content is not a complete overview of the present disclosure, and its intention is not to point out the important / key elements of the embodiments of the present invention or to define the scope of the present invention. After referring to the following embodiments, those with ordinary knowledge in the technical field to which the present invention belongs can easily understand the basic spirit of the present invention and the technical means and embodiments adopted by the present invention. DETAILED DESCRIPTION

[0024] In order to make the description of the disclosure of the present invention more detailed and complete, the following is an illustrative description of the implementation methods and specific examples of the present invention; however, this is not the only form of implementing or applying the specific examples of the present invention. The various embodiments disclosed below can be combined or replaced with each other under beneficial circumstances, and other embodiments can be added to one embodiment without further recording or explanation.

[0025] The advantages, features and technical methods achieved by the present invention will be described in more detail with reference to exemplary embodiments so as to be more easily understood, and the present invention may be implemented in different forms, so it should not be understood to be limited to the embodiments described herein. On the contrary, for those with ordinary knowledge in the relevant technical field, the provided embodiments will make the present disclosure more thorough and comprehensive and completely convey the scope of the present invention, and the present invention will only be defined by the scope of the attached patent application.

[0026] Unless otherwise defined, all terms (including technical and scientific terms) and proper nouns used in the following text have substantially the same meaning as generally understood by technicians in the field to which the invention relates, and those terms defined in commonly used dictionaries, for example, should be understood to have meanings consistent with the content of the relevant field, and will not be understood in an overly idealized or overly formal sense unless clearly defined in the following text.

[0027] The present invention provides an aqueous hot melt adhesive, which comprises 100 parts by weight of an aqueous polyolefin resin, 40 to 85 parts by weight of a powder wax and 25 to 85 parts by weight of a powder tackifier, wherein the total amount of powder of the aqueous hot melt adhesive, i.e. the total weight of the powder wax and the powder tackifier, accounts for 45wt% to 60wt% of the total weight of the aqueous hot melt adhesive.

[0028] The water-based hot melt adhesive of the present invention can be coated on the surface of a polyolefin spunbonded nonwoven fabric for medical packaging after adding water as a solvent, and a water-based hot melt adhesive coated nonwoven fabric can be prepared after heating to remove the solvent. The water-based hot melt adhesive coated nonwoven fabric can provide good air permeability, so that the water-based hot melt adhesive coated nonwoven fabric and a flexible sheet or a blister container can be heat-sealed at the periphery and then steam sterilized or EO gas sterilized. Furthermore, the water-based hot melt adhesive of the present invention can provide good thermal adhesion and peelability, and the medical packaging material prepared therefrom can have the required heat sealing strength. When the packaging material is torn open, the packaging material will be stably disconnected from the adhesive layer at the heat-sealed portion of the water-based hot melt adhesive to maintain the heat sealing stability and reduce the pollution caused by the shedding of the substrate fibers.

[0029] The water-based hot melt adhesive of the present invention contains a high total amount of powder so that when the water-based hot melt adhesive is coated on the polyolefin spunbonded nonwoven fabric for medical packaging, the coating can maintain appropriate gaps while still providing the expected sealing strength and adhesion to the nonwoven fabric.

[0030] The water-based hot melt adhesive of the present invention is prepared by adding powder wax, powder tackifier and water as a solvent to water-based polyolefin resin, and then fully mixing and dispersing to form a coating liquid for subsequent coating process. After coating, the solvent is evaporated by heating to obtain the water-based hot melt adhesive of the present invention. The water-based hot melt adhesive of the present invention can be directly heat-sealed at 90° C. to 150° C., eliminating the mixing step required by traditional hot melt adhesives, and can achieve the required adhesion and specific air permeability of hot melt adhesives after application.

[0031] In a preferred embodiment of the present invention, the water-based hot melt adhesive preferably comprises 100 parts by weight of water-based polyolefin resin, 45 to 80 parts by weight of powder wax and 30 to 80 parts by weight of powder tackifier, wherein the total weight of the powder of the water-based hot melt adhesive, i.e., the total weight of the powder wax and the powder tackifier, accounts for 48wt% to 57wt% of the total weight of the water-based hot melt adhesive. If the total weight of the powder is too little, the coating will have insufficient air permeability, and if the total weight of the powder is too much, the sealing strength will be too low.

[0032] The water-based hot melt adhesive of the present invention uses water-based polyolefin resin as the hot melt adhesive matrix. The formed water-based hot melt adhesive coating has high adhesion to the substrate when applied to the polyolefin-based spunbonded non-woven fabric substrate. Because the polyolefin resin is a low-polarity material, the formed water-based hot melt adhesive coated non-woven fabric is heat-sealed with a flexible packaging material such as a polyethylene substrate or a polypropylene substrate. The difference in surface polarity between the two is low, so the adhesion strength at the interface is high, which can maintain the heat sealing stability and reduce the fiber shedding when the non-woven fabric substrate is torn open. The water-based polyolefin resin used in the water-based hot melt adhesive of the present invention can be a modified or unmodified polyolefin resin, and its glass transition temperature (glass transition temperature, Tg) can be less than 0°C and the melting point can be higher than 90°C. Preferably, the glass transition temperature (Tg) can be less than -100°C and the melting point can be higher than 120°C. The water-based polyolefin resin used in the present invention may be, for example, a group consisting of water-based polyethylene resin, water-based polypropylene resin, water-based polybutylene resin, water-based oxidized polyethylene resin, and combinations thereof, but is not limited thereto.

[0033] The water-based polyolefin resin suitable for the water-based hot melt adhesive of the present invention can be commercially available, such as ALTRIX WPE-09838 purchased from Kolon Chemical; CHEMIPEARL TM S300, S500; Japan's Unitika arrowbase SB-1030N; US MICA's HME-118-B, etc., but not limited to these.

[0034] The powder wax of the water-based hot melt adhesive of the present invention is used to reduce the melt viscosity and surface viscosity of the water-based hot melt adhesive and adjust the fluidity and wettability of the hot melt adhesive, but will not significantly reduce the adhesive properties of the water-based hot melt adhesive. The content of the powder wax of the water-based hot melt adhesive of the present invention can be between 40 parts by weight and 85 parts by weight per hundred parts by weight of the water-based polyolefin resin, and is preferably between 45 parts by weight and 80 parts by weight. Furthermore, in order to help the coating formed by the water-based hot melt adhesive of the present invention on the polyolefin-based spunbond non-woven fabric substrate have good air permeability, the particle size (D50) of the powder wax can be between 3 microns (μm) and 20 microns (μm), and is preferably between 3 microns (μm) and 15 microns (μm).

[0035] The glass transition temperature (Tg) of the powder wax suitable for the water-based hot melt adhesive of the present invention may be less than 0°C, and the melting point is between 70°C and 180°C. The powder wax used in the present invention may be, for example, a group consisting of commercially available Fischer-Tropsch synthetic powder wax, polypropylene powder wax, polyethylene powder wax, oxidized polyethylene powder wax, microcrystalline wax and combinations thereof, but is not limited thereto. Applicable Fischer-Tropsch synthetic powder wax may be, for example, Sasolwax Spray 30-G, Spray 30G-M, Spray 30G-EF, Spray 105, Spray 105-G, Spray 105G-EF, Sasolwax Aqua 30-G, Aqua 30G-EF, etc. obtained from Sasol Chemicals Pacific Ltd. of South Africa; Applicable polypropylene powder wax may be, for example, BYK's 913, 914. Germany's Münzing Chemie MP2120, etc.; Suitable polyethylene powder waxes may be, for example, BYK's 925, 929N, Münzing Chemie of Germany MO4715, etc., but not limited thereto.

[0036] The use of a tackifier in the water-based hot melt adhesive of the present invention can reduce the melt viscosity of the water-based hot melt adhesive, improve the wettability and initial adhesion of the adherend, and adjust the heat resistance temperature of the hot melt adhesive. The use of a powder tackifier in the water-based hot melt adhesive of the present invention can achieve a high total powder amount, so that when the water-based hot melt adhesive is coated on an olefin-based spunbond non-woven fabric for medical packaging, the coating can maintain appropriate gaps but still provide the expected sealing strength and adhesion to the non-woven fabric as a whole. The amount of the powder tackifier used in the water-based hot melt adhesive of the present invention can be between 25 parts by weight and 85 parts by weight per hundred parts by weight of the water-based polyolefin resin, and preferably between 30 parts by weight and 80 parts by weight.

[0037] In order to make the coating formed by the water-based hot melt adhesive of the present invention on the polyolefin-based spunbonded non-woven fabric substrate have good air permeability and sealing strength, the particle size (D50) of the powder thickener used in the water-based hot melt adhesive of the present invention is similar to the particle size (D50) of the powder wax, which can be between 3 microns (μm) and 35 microns (μm), preferably between 5 microns (μm) and 30 microns (μm). The glass transition temperature (Tg) of the powder thickener is greater than 0°C and the melting point is between 90°C and 160°C. In the water-based hot melt adhesive of the present invention, the amount of the powder thickener used can be adjusted according to the amount of powder wax used, so that the total amount of powder in the water-based hot melt adhesive, that is, the total amount of powder thickener and powder wax, is between 45wt% and 60wt% of the water-based hot melt adhesive, and preferably between 48wt% and 57wt%. The weight ratio of powder wax to the powder thickener can be between 0.6:1 and 3:1. If the amount of powder wax used is too little, the uniform fracture characteristics of the adhesive layer cannot be achieved. If the amount of powder wax used is too much, the sealing strength will be insufficient.

[0038] The powder tackifier suitable for the water-based hot melt adhesive of the present invention can be a petroleum resin powder or a hydrogenated petroleum resin powder having a softening point higher than 90°C, such as a group consisting of C5 petroleum resin powder, C9 petroleum resin powder, C5 / C9 copolymerized petroleum resin powder, hydrogenated C9 petroleum resin powder and combinations thereof. For example, the commercially available Cray Valley Company of the United States 95. 98. STS, Extra, W-90, W-110, W-120, W-140, Regalite provided by Synthomer, UK TM R1090, Regalite TM R1125, YL-90, YL-120H provided by Yuan Liang Industrial Co., Ltd., but not limited to these.

[0039] In another embodiment of the water-based hot melt adhesive of the present invention, the water-based hot melt adhesive may further include a water-based emulsion tackifier, which, in addition to providing the aforementioned reduction in the melt viscosity of the water-based hot melt adhesive, the improvement of the wettability and initial adhesion of the adherend, and the adjustment of the heat resistance temperature of the hot melt adhesive, further helps the overall compatibility and coating of the water-based hot melt adhesive. However, if the water-based hot melt adhesive contains an excessive amount of emulsion tackifier, it may cause the water-based hot melt adhesive coating to penetrate into the non-woven fabric after coating, affecting the overall air permeability. In another embodiment of the present invention, the water-based hot melt adhesive may include 10 to 60 parts by weight of the water-based emulsion tackifier, relative to every 100 parts by weight of the water-based polyolefin resin.

[0040] The aqueous emulsion tackifier suitable for the aqueous hot melt adhesive of the present invention can be a resin emulsion with a glass transition temperature (Tg) higher than 0°C, such as petroleum resin emulsion, rosin ester and its derivative emulsion, terpene resin and its modified resin emulsion, thermoplastic phenolic resin emulsion, low molecular weight polystyrene emulsion or ethylene acrylic acid copolymer emulsion, etc. Suitable petroleum resin emulsions include aliphatic hydrocarbon resin emulsions, cycloaliphatic hydrocarbon resin emulsions, aromatic hydrocarbon resin emulsions, aliphatic / aromatic copolymer resin emulsions, such as C5 aliphatic hydrocarbon resin emulsions, C9 aromatic hydrocarbon resin emulsions and C5 / C9 aliphatic / aromatic copolymer resin emulsions, hydrogenated petroleum resin emulsions, etc. Suitable rosin ester and its derivative emulsions include rosin resin and its derivative emulsions such as gum rosin emulsions, wood rosin emulsions and tall oil rosin and its derivative emulsions. Applicable terpene resins and modified resin emulsions thereof include terpene resin emulsions, hydrogenated terpene resin emulsions, aromatic modified resin emulsions, terpene-phenolic resin emulsions, etc. In the present invention, these aqueous emulsion tackifiers can be mixed. In one embodiment of the present invention, the aqueous hot melt adhesive can use one or more aqueous emulsion tackifiers.

[0041] Suitable aqueous emulsion tackifiers can be commercially available, such as emulsified rosin esters provided by DRT, France. RE802, water-based rosin acid emulsion RA702, terpene phenolic resin emulsion TR602, C5 resin emulsion DP1124, water-based rosin ester SUPER ESTER E720W provided by Arakawa Chemical Industries, Japan, and ethylene acrylic acid copolymer aqueous dispersion provided by Michelman Company, USA Prime4983R, Prime 4990R, Prime 4983-40R, Aquacer 1061, an ethylene acrylic acid copolymer latex provided by BYK, and Addtack, a rosin ester latex provided by West Tech Chemical in China TM 880L, etc., but not limited to.

[0042] The water-based hot melt adhesive disclosed in the present invention may further include other additives, such as wetting dispersants, defoamers, thickeners, etc., which are beneficial to the coating processability of the water-based hot melt adhesive; antioxidants, UV stabilizers, antibacterial agents, antistatic agents, etc., which are added to increase the functionality of the water-based hot melt adhesive. The types and amounts of these additives can be selected by those skilled in the art according to actual needs.

[0043] The present invention further provides a water-based hot melt adhesive coated nonwoven fabric, which comprises a polyolefin-based spunbond nonwoven fabric substrate and a coating formed by the water-based hot melt adhesive on at least one surface of the substrate. The water-based hot melt adhesive coated nonwoven fabric can have an air permeability of less than 180 seconds (TAPPI (Technical Association of the Pulp and Paper industry) T-460) and a sealing strength greater than 220g / 15mm (ASTM (American Society for Testing and Materials) F-88).

[0044] The "sealing strength" mentioned herein refers to the tensile force required to separate two sealed flexible sheets, which is measured in a "T-separation" test at a tensile speed of 200 mm / min according to ASTM F88.

[0045] The "air permeability" mentioned herein refers to the air resistance of gas passing through a breathable sheet, which is measured according to TAPPI T-460 standard as the air resistance of 100 cc of gas passing through a circular area of ​​about 1 square inch at a pressure difference of 1.22 kPa.

[0046] The olefin spunbond nonwoven fabric suitable for the water-based hot melt adhesive coated nonwoven fabric of the present invention can be selected and used in medical packaging. The density is between 40g / m 2 Up to 80g / m 2 DuPont For example 1073B, 1059B, 2FS, etc., but not limited to.

[0047] The water-based hot melt adhesive coated non-woven fabric of the present invention can be evenly coated on the olefin-based spunbond non-woven fabric substrate or locally coated in a specific area, and the coating amount is between 10 g / m 2 Up to 20g / m 2 , preferably between 12g / m 2 Up to 18g / m 2 .

[0048] The packaging substrate suitable for sealing with the water-based hot melt adhesive coated non-woven fabric of the present invention may be, for example, polyethylene terephthalate (PET), polyethylene terephthalate glycol-1,4-cyclohexanedimethanol (PETG), polyvinyl chloride (PVC), polystyrene (PS), polypropylene (PP), polyethylene (PE), polycarbonate (PC), nylon (Nylon) film or its blister hard substrate, but is not limited thereto.

[0049] The water-based hot melt adhesive coated nonwoven fabric of the present invention can be thermally bonded to another packaging substrate, such as the aforementioned substrate, at a temperature of 90°C to 150°C, and the sealing strength after bonding is greater than 220g / 15mm, preferably greater than 250g / 15mm.

[0050] The preparation method of the water-based hot melt adhesive coated non-woven fabric disclosed in the present invention includes adding powder wax, powder thickener and water as a solvent to a water-based polyolefin resin, fully stirring and dispersing, and forming a water-based hot melt adhesive emulsion. The prepared water-based hot melt adhesive emulsion can be coated on a polyolefin-based spunbond non-woven fabric substrate, and dried at a temperature of 60°C to 100°C to remove the solvent to form a water-based hot melt adhesive coated non-woven fabric. The coating method of the water-based hot melt adhesive can adopt, for example, a roller coating method, a blade coating method, a roller coating method, a spin coating method, a spray coating method, a slit coating method, a wind knife coating method and other coating methods commonly used in this technical field, but not limited thereto.

[0051] The water-based hot melt adhesive coated nonwoven fabric of the present invention has good air permeability after being heat-sealed with a flexible sheet or a blister container at the periphery, so as to facilitate steam sterilization or EO gas sterilization process, and at the same time has reliable sealing strength and peelability, so that when the heat-sealed seal is peeled off, the water-based hot melt adhesive interface can be stably disconnected, thereby reducing the problem of nonwoven fabric fiber shedding causing medical device contamination.

[0052] The following examples are used to further illustrate the present invention, but the contents of the present invention are not limited thereto.

[0053] Example

[0054] The materials used in the embodiments of the present invention are as follows:

[0055] WPE-09838: polyethylene latex, melting point 145°C, glass transition temperature (Tg) -120°C, solid content 25%, solvent water, purchased from Gonglong Chemical Co., Ltd.

[0056] Arrowbase SB-1030N: polyethylene latex, melting point of 145°C, glass transition temperature (Tg) of -120°C, solid content of 26%, solvent of water, purchased from Unitika Co., Ltd. of Japan.

[0057] DL 326PA: styrene-butadiene rubber latex, melting point of 230.9°C, glass transition temperature (Tg) of -42.1°C, solid content of 50%, solvent of water, purchased from Trinseo, USA.

[0058] EAF-68: ethylene-vinyl acetate-acrylic acid copolymer latex, with a melting point of 240° C., a glass transition temperature (Tg) of −35° C., a solid content of 59.5%, and a solvent of water, purchased from Wacker Chemie AG, Germany.

[0059] Prime 4983-40R: ethylene acrylic acid copolymer latex, melting point of 140°C, glass transition temperature (Tg) of 6.2°C, solid content of 40%, solvent of water, purchased from Michelman Company, USA.

[0060] Addtack TM 880L: rosin ester emulsion, softening point of 75 to 85°C, glass transition temperature (Tg) of 33.4°C, solid content of 55%, solvent is water, purchased from West Tech Chemical Co., Ltd., China.

[0061] RE802: rosin glycerol ester emulsion, softening point of 70°C, glass transition temperature (Tg) of 17.9°C, solid content of 52%, solvent is water, purchased from DRT Company of France.

[0062] Sasolwax Spray 30G-M: Fischer-Tropsch synthetic powder wax, melting point of 96 to 100°C, glass transition temperature (Tg) of about -120°C, average particle size of 9 to 11 μm, purchased from Sasol Limited of South Africa.

[0063] MO4715: oxidized polyethylene powder wax, with a melting point of 108 to 116° C., a glass transition temperature (Tg) of about −120° C., and an average particle size of 6 μm, purchased from Münzing Chemie, Germany.

[0064] W-140: C9 petroleum resin powder, softening point of 140°C, glass transition temperature (Tg) of 90°C, number average molecular weight (Mn) of 1200, where number average molecular weight (Mn) is total molecular mass (g) / total molar number (mol), average particle size of 5 to 10 μm, purchased from Cray Valley Chemical Co., Ltd., USA.

[0065] W-140(L): C9 petroleum resin powder, softening point of 140°C, glass transition temperature (Tg) of 90°C, number average molecular weight (Mn) of 1200 g / mol, average particle size of 10 to 30 μm, purchased from Cray Valley Chemical Co., Ltd., USA.

[0066] W-120: C9 petroleum resin powder, softening point of 120°C, glass transition temperature (Tg) of 70°C, number average molecular weight (Mn) of 950 g / mol, average particle size of 10 to 20 μm, purchased from Cray Valley Chemical Co., Ltd., USA.

[0067] YL-90: C9 petroleum resin, softening point of 100°C, glass transition temperature (Tg) of 50°C, average molecular weight (Mn) of 750 g / mol, average particle size of 30 to 40 μm, purchased from Yuanliang Industrial Co., Ltd.

[0068] BYK-3450: polyether-modified siloxane wetting and dispersing agent, purchased from BYK, Germany.

[0069] Wet 240: polysiloxane wetting and dispersing agent, purchased from Evonik Industries of Germany.

[0070] AS-1125: acrylic thickener, purchased from Cognis GmbH, Germany.

[0071] BYK-025: polysiloxane defoamer, solid content of 18.5%, solvent is dipropylene glycol monomethyl ether, purchased from BYK, Germany.

[0072] 2FS: high-density polyethylene spunbond nonwoven fabric substrate, purchased from DuPont, USA.

[0073] Example 1

[0074] 27.36 parts by weight of polyethylene latex (WPE-09838), 3.76 parts by weight of oxidized polyethylene powder wax ( MO 4715), 3.76 parts by weight of C9 petroleum resin powder ( W-140(L)), 0.06 parts by weight of a dispersant (BYK-3450), 1.06 parts by weight of a thickener (AS-1125), 0.04 parts by weight of a defoamer (BYK-025) and 37.4 parts by weight of deionized water were mixed and stirred for 1 hour to uniformly disperse them to form an aqueous hot melt adhesive solution.

[0075] The aqueous hot melt adhesive solution is coated on a high-density polyethylene spunbond nonwoven fabric substrate ( 2FS), dried at 80°C for 2 minutes to form a 14.6 g / m 2 Aqueous hot melt adhesive coating is used to prepare an aqueous hot melt adhesive coated nonwoven fabric.

[0076] The obtained water-based hot melt adhesive coated nonwoven fabric was subjected to air permeability test, heat sealing strength test and peeling test according to the method described below. The test results are shown in Table 1 below.

[0077] Example 2

[0078] 29.76 parts by weight of polyethylene latex (WPE-09838), 5.04 parts by weight of Fischer-Tropsch wax (Sasolwax Spray 30G-M), 2.48 parts by weight of C9 petroleum resin powder ( W-140), 0.06 parts by weight of a dispersant (BYK-3450), 0.96 parts by weight of a thickener (AS-1125), 0.04 parts by weight of a defoamer (BYK-025) and 22.9 parts by weight of deionized water were mixed and stirred for 1 hour to uniformly disperse them to form an aqueous hot melt adhesive solution.

[0079] The aqueous hot melt adhesive solution is coated on a high-density polyethylene spunbond nonwoven fabric substrate ( 2FS), dried at 80°C for 2 minutes to form a 15.1 g / m 2 Aqueous hot melt adhesive coating is used to prepare an aqueous hot melt adhesive coated nonwoven fabric.

[0080] The obtained water-based hot melt adhesive coated nonwoven fabric was subjected to air permeability test, heat sealing strength test and peeling test according to the method described below. The test results are shown in Table 1 below.

[0081] Example 3

[0082] 23.81 parts by weight of polyethylene latex (WPE-09838), 2.7 parts by weight of rosin ester emulsion (Addtack TM 880L), 3.76 parts by weight of polypropylene powder wax ( MP 2120), 3.76 parts by weight of C9 petroleum resin powder ( W-140), 0.06 parts by weight of a dispersant (BYK-3450), 1.06 parts by weight of a thickener (AS-1125), 0.04 parts by weight of a defoamer (BYK-025) and 32.6 parts by weight of deionized water were mixed and stirred for 1 hour to uniformly disperse them to form an aqueous hot melt adhesive solution.

[0083] The aqueous hot melt adhesive solution is coated on a high-density polyethylene spunbond nonwoven fabric substrate ( 2FS), dried at 80°C for 2 minutes to form a 17.1 g / m 2 Aqueous hot melt adhesive coating is used to prepare an aqueous hot melt adhesive coated nonwoven fabric.

[0084] The obtained water-based hot melt adhesive coated nonwoven fabric was subjected to air permeability test, heat sealing strength test and peeling test according to the method described below. The test results are shown in Table 1 below.

[0085] Example 4

[0086] 26.78 parts by weight of polyethylene latex (WPE-09838), 1.35 parts by weight of rosin ester emulsion (Addtack TM 880L), 3.76 parts by weight of Fischer-Tropsch wax powder (Sasolwax Spray30G-M), 3.76 parts by weight of C9 petroleum resin powder ( W-140), 0.06 parts by weight of a dispersant (BYK-3450), 1.06 parts by weight of a thickener (AS-1125), 0.04 parts by weight of a defoamer (BYK-025) and 31.0 parts by weight of deionized water were mixed and stirred for 1 hour to uniformly disperse them to form an aqueous hot melt adhesive solution.

[0087] The aqueous hot melt adhesive solution is coated on a high-density polyethylene spunbond nonwoven fabric substrate ( 2FS), dried at 80°C for 2 minutes to form a 14.0 g / m 2 Aqueous hot melt adhesive coating is used to prepare an aqueous hot melt adhesive coated nonwoven fabric.

[0088] The obtained water-based hot melt adhesive coated nonwoven fabric was subjected to air permeability test, heat sealing strength test and peeling test according to the method described below. The test results are shown in Table 1 below.

[0089] Example 5

[0090] 22.32 parts by weight of polyethylene latex (WPE-09838), 1.35 parts by weight of rosin ester emulsion (Addtack TM 880L), 2.79 parts by weight of ethylene acrylic acid copolymer latex ( Prime4983-40R), 3.76 parts by weight of Fischer-Tropsch wax powder (Sasolwax Spray 30G-M), 3.76 parts by weight of C9 petroleum resin powder ( W-140), 0.06 parts by weight of a dispersant (BYK-3450), 1.06 parts by weight of a thickener (AS-1125), 0.04 parts by weight of a defoamer (BYK-025) and 32.7 parts by weight of deionized water were mixed and stirred for 1 hour to uniformly disperse them to form an aqueous hot melt adhesive solution.

[0091] The aqueous hot melt adhesive solution is coated on a high-density polyethylene spunbond nonwoven fabric substrate ( 2FS), dried at 80°C for 2 minutes to form a 15.5 g / m 2 Aqueous hot melt adhesive coating is used to prepare an aqueous hot melt adhesive coated nonwoven fabric.

[0092] The obtained water-based hot melt adhesive coated nonwoven fabric was subjected to air permeability test, heat sealing strength test and peeling test according to the method described below. The test results are shown in Table 1 below.

[0093] Example 6

[0094] 19.34 parts by weight of polyethylene latex (WPE-09838), 2.7 parts by weight of rosin ester emulsion (Addtack TM 880L), 2.79 parts by weight of copolymer latex ( Prime 4983-40R), 3.76 parts by weight of Fischer-Tropsch wax powder (Sasolwax Spray 30G-M), 3.76 parts by weight of C9 petroleum resin powder ( W-140), 0.06 parts by weight of a dispersant (BYK-3450), 0.96 parts by weight of a thickener (AS-1125), 0.04 parts by weight of a defoamer (BYK-025) and 27.6 parts by weight of deionized water were mixed and stirred for 1 hour to uniformly disperse them to form an aqueous hot melt adhesive solution.

[0095] The aqueous hot melt adhesive solution is coated on a high-density polyethylene spunbond nonwoven fabric substrate ( 2FS), dried at 80°C for 2 minutes to form a 15.9 g / m 2 Aqueous hot melt adhesive coating is used to prepare an aqueous hot melt adhesive coated nonwoven fabric.

[0096] The obtained water-based hot melt adhesive coated nonwoven fabric was subjected to air permeability test, heat sealing strength test and peeling test according to the method described below. The test results are shown in Table 1 below.

[0097] Example 7

[0098] 29.84 parts by weight of polyethylene latex (SB-1030N), 3.76 parts by weight of Fischer-Tropsch wax (Sasolwax Spray 30G-M), 3.76 parts by weight of C9 petroleum resin powder ( W-140), 0.12 parts by weight of a dispersant (BYK-3450), 2.86 parts by weight of a thickener (AS-1125), 0.08 parts by weight of a defoamer (BYK-025) and 87.8 parts by weight of deionized water were mixed and stirred for 1 hour to uniformly disperse them to form an aqueous hot melt adhesive solution.

[0099] The aqueous hot melt adhesive solution is coated on a high-density polyethylene spunbond nonwoven fabric substrate ( 2FS), dried at 80°C for 2 minutes to form a 15.3 g / m 2 Aqueous hot melt adhesive coating is used to prepare an aqueous hot melt adhesive coated nonwoven fabric.

[0100] The obtained water-based hot melt adhesive coated nonwoven fabric was subjected to air permeability test, heat sealing strength test and peeling test according to the method described below. The test results are shown in Table 1 below.

[0101] Comparative Example 1

[0102] 13.1 parts by weight of ethylene acrylic acid copolymer latex ( Prime 4983-40R), 1.5 parts by weight of rosin ester emulsion ( RE 802), 3.75 parts by weight of Fischer-Tropsch wax powder (Sasolwax Spray30G-M), 1.875 parts by weight of C9 petroleum resin powder ( W-120), 1.875 parts by weight of C9 petroleum resin powder (YL-90), 0.04 parts by weight of dispersant (BYK-3450), 0.04 parts by weight of defoamer (BYK-025) and 45.6 parts by weight of deionized water were mixed and stirred for 1 hour to make them uniformly dispersed to form an aqueous hot melt adhesive solution.

[0103] The aqueous hot melt adhesive solution is coated on a high-density polyethylene spunbond nonwoven fabric substrate ( 2FS), dried at 80°C for 2 minutes to form a 13.9 g / m 2 Aqueous hot melt adhesive coating is used to prepare an aqueous hot melt adhesive coated nonwoven fabric.

[0104] The obtained water-based hot melt adhesive coated nonwoven fabric was subjected to air permeability test, heat sealing strength test and peeling test according to the method described below. The test results are shown in Table 1 below.

[0105] Comparative Example 2

[0106] 7.68 parts by weight of styrene-butadiene rubber (DL 326PA), 7.2 parts by weight of ethylene acrylic acid copolymer latex ( Prime 4983-40R), 1.6 parts by weight of ethylene-vinyl acetate copolymer latex ( EAF 68), 7.52 parts by weight of C9 petroleum resin powder ( W-140), 0.06 parts by weight of dispersant ( Wet 240, 0.04 parts by weight of a defoamer (BYK-025) and 41.6 parts by weight of deionized water were mixed and stirred for 1 hour to uniformly disperse them to form an aqueous hot melt adhesive solution.

[0107] The aqueous hot melt adhesive solution is coated on a high-density polyethylene spunbond nonwoven fabric substrate ( 2FS), dried at 80°C for 2 minutes to form a 10.0 g / m 2 Aqueous hot melt adhesive coating is used to prepare an aqueous hot melt adhesive coated nonwoven fabric.

[0108] The obtained water-based hot melt adhesive coated nonwoven fabric was subjected to air permeability test, heat sealing strength test and peeling test according to the method described below. The test results are shown in Table 1 below.

[0109] Coating weight measurement, air permeability test, heat seal strength test and peel test evaluation methods

[0110] Coating weight measurement: Using a circular cutter (Sample Cutter 240 / 100, purchased from Hans Schmidt & Co GmbH, Germany), according to the test standard of EN ISO 536, the weight of the aforementioned water-based hot melt adhesive coated non-woven fabric and the uncoated high-density polyethylene spunbond non-woven fabric substrate were measured respectively. The weight of the water-based hot melt adhesive coating was obtained by subtracting the two. The unit is grams per square meter (g / m2). 2 (gsm).

[0111] Air permeability test: using an air permeability tester (Model 4980-D, purchased from Liansheng Instruments), according to the test standard of TAPPI T-460, the average number of seconds required for 100cc of air to pass through the aforementioned water-based hot melt adhesive coated nonwoven fabric was measured.

[0112] Measurement of sealing strength: The HDPE film, Teflon cloth and the aforementioned water-based hot melt adhesive coated non-woven fabric were heat pressed using a heat sealing tester (BS-25, purchased from Dam Precision Machinery). The upper plate temperature was set to 123 degrees Celsius, the lower plate temperature was set to room temperature, the heat sealing pressure was set to 1.5 kg and the pressing seconds were set to 1.5 seconds. The resulting heat-sealed composite product was cut into 15 mm wide strip specimens and the maximum tensile force was measured using a tensile tester (AI-3000, purchased from Gaotie Technology) according to the ASTM F-88 test standard, which is the sealing strength.

[0113] Peeling test: The HDPE film in the aforementioned heat-sealed synthetic product was torn off from the water-based hot melt adhesive coated non-woven fabric by hand, and the high-density polyethylene spunbond non-woven fabric substrate after torn off was visually observed to see whether there was fiber peeling. If no fiber peeling was found on the surface of the substrate, it was evaluated as 0, and if fiber peeling was found on the surface of the substrate, it was evaluated as ×.

[0114] Table 1: Coating weight, air permeability, heat seal strength and peel test results of water-based hot melt adhesive coated nonwoven fabrics of the embodiments and comparative examples

[0115]

[0116]

[0117] It can be seen from Table 1 that the water-based hot melt adhesive coated non-woven fabrics prepared in Examples 1 to 7 not only have good air permeability, but also have sufficient sealing strength after heat sealing with the HDPE film. At the same time, when the HDPE film is torn off, the high-density polyethylene spunbond non-woven fabric substrate will not have the problem of fiber detachment.

[0118] Although the present invention has been disclosed as above by the embodiments, it is not intended to limit the present invention. Any person skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be based on the scope defined by the claims.

Claims

1. A water-based hot melt adhesive comprising: 100 parts by weight of an aqueous polyolefin resin; 40 to 85 parts by weight of powdered wax; and 25 to 85 parts by weight of a powder thickener; The total amount of the powder of the water-based hot melt adhesive accounts for 45wt% to 60wt% of the total weight of the water-based hot melt adhesive.

2. The water-based hot melt adhesive according to claim 1, wherein the particle size of the powder wax is between 3 microns and 20 microns.

3. The water-based hot melt adhesive according to claim 1, wherein the particle size of the powdered tackifier is between 3 microns and 35 microns.

4. The water-based hot melt adhesive according to claim 1, wherein the weight ratio of the powder wax to the powder tackifier is between 0.6:1 and 3:

1.

5. The water-based hot melt adhesive according to claim 1, wherein the water-based hot melt adhesive comprises: 100 parts by weight of the waterborne polyolefin resin; 45 to 80 parts by weight of the powder wax; and 30 to 80 parts by weight of the powder thickener; The total amount of the powder of the water-based hot melt adhesive accounts for 48wt% to 57wt% of the total weight of the water-based hot melt adhesive.

6. The water-based hot melt adhesive according to claim 1 further comprises an aqueous emulsion tackifier.

7. The water-based hot melt adhesive according to claim 6, wherein the amount of the water-based emulsion tackifier used is between 10 parts by weight and 60 parts by weight.

8. The water-based hot melt adhesive according to claim 1, wherein the glass transition temperature of the water-based polyolefin resin is less than 0°C and the melting point is higher than 90°C, the glass transition temperature of the powder wax is less than 0°C and the melting point is between 70°C and 180°C, and the glass transition temperature of the powder tackifier is greater than 0°C and the melting point is between 90°C and 160°C. 9 . The water-based hot melt adhesive according to claim 1 , wherein the glass transition temperature of the water-based hot melt adhesive is between -120° C. and -50° C.

10. The water-based hot melt adhesive according to claim 1, wherein the water-based polyolefin resin is selected from the group consisting of water-based polyethylene resin, water-based polypropylene resin, water-based polybutylene resin, water-based oxidized polyethylene resin and combinations thereof. 11 . The water-based hot melt adhesive according to claim 1 , wherein the powder wax is selected from the group consisting of Fischer-Tropsch synthesis powder wax, polypropylene powder wax, polyethylene powder wax, oxidized polyethylene powder wax, microcrystalline wax and combinations thereof.

12. The water-based hot melt adhesive according to claim 1, wherein the powder tackifier is selected from the group consisting of C5 petroleum resin powder, C9 petroleum resin powder, C5 / C9 copolymerized petroleum resin powder, hydrogenated C9 petroleum resin powder and combinations thereof.

13. The aqueous hot melt adhesive according to claim 6, wherein the aqueous emulsion tackifier is selected from the group consisting of petroleum resin emulsion, rosin ester and its derivative emulsion, terpene resin and its modified resin emulsion, thermoplastic phenolic resin emulsion, low molecular weight polystyrene emulsion, ethylene acrylic acid copolymer emulsion and combinations thereof.

14. A water-based hot melt adhesive coated nonwoven fabric, comprising a polyolefin-based spunbonded nonwoven fabric substrate and a water-based hot melt adhesive coating formed on at least one surface of the polyolefin-based spunbonded nonwoven fabric substrate, wherein the water-based hot melt adhesive configured to form the water-based hot melt adhesive coating comprises: 100 parts by weight of an aqueous polyolefin resin; 40 to 85 parts by weight of powdered wax; and 25 to 85 parts by weight of a powder thickener; The total amount of the powder of the water-based hot melt adhesive accounts for 45wt% to 60wt% of the total weight of the water-based hot melt adhesive.

15. The water-based hot melt adhesive coated non-woven fabric according to claim 14, wherein the air permeability of the water-based hot melt adhesive coated non-woven fabric is less than 180 seconds and the sealing strength is greater than 220g / 15mm.

16. The water-based hot melt adhesive coated nonwoven fabric according to claim 14, wherein the coating amount of the water-based hot melt adhesive on the polyolefin-based spunbond nonwoven fabric substrate is 10 g / m 2 Up to 20g / m 2 between.

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