JP-7856361-B2 - Absorbent materials and hygiene products

JP7856361B2JP 7856361 B2JP7856361 B2JP 7856361B2JP-7856361-B2

Inventors

ユン・キョン・ド

Assignees

エルジー・ケム・リミテッド

Dates

Publication Date: 20260511
Application Date: 20231116
Priority Date: 20221116

Claims (10)

First nonwoven fabric and, The second nonwoven fabric, The first and second nonwoven fabrics are interposed to form a superabsorbent resin layer, The superabsorbent resin layer comprises a superabsorbent resin and an adhesive. The superabsorbent resin layer is bonded to the first and second nonwoven fabrics via an adhesive, and does not contain pulp. The superabsorbent resin layer is formed by sequentially laminating a first coating layer of superabsorbent resin, a first coating layer of adhesive, a second coating layer of superabsorbent resin, a second coating layer of adhesive, and a third coating layer of superabsorbent resin. The following conditions (1) and (2) must be met: Absorbent material. (1) The absorbent was vibrated 100 times at a frequency of 65 times/min and an amplitude of 15 mm, and the amount of superabsorbent resin remaining in the absorbent without leakage was measured. The fixation rate was 90% or more. (2) After dyeing the absorbent material with a dye and drying it, and after confirming that only the superabsorbent resin portion has been selectively dyed, the area of the dyed portion is measured with a colorimeter and the filling rate is 90% or more.
The superabsorbent resin layer is formed by applying the superabsorbent resin and adhesive alternately two or more times. The absorbent according to claim 1.
The thickness of the superabsorbent resin layer is 5 mm or less. The absorbent according to claim 1.
The superabsorbent resin layer contains 100 g or more of superabsorbent resin per unit area ( m² ). The absorbent according to claim 1.
The aforementioned superabsorbent resin is A base resin comprising an acrylic acid monomer containing acidic groups, in which at least a portion of the acidic groups are neutralized, and a crosslinked polymer of an internal crosslinking agent, A superabsorbent resin comprising a surface crosslinked layer formed on the base resin, wherein the crosslinked polymer is further crosslinked via a surface crosslinking agent, The following conditions 1) through 4) must be met: The absorbent according to claim 1. 1) The water retention capacity (CRC) measured by EDANA NWSP 241.0. R2(15) is 32 g/g to 40 g/g. 2) The water-soluble component measured after 16 hours of swelling by EDANA NWSP 270.0. R2(15) is 10% by weight or less. 3) The absorption rate by the vortex method (vortex time) is 30 seconds or less. 4) Bulk density measured by EDANA NWSP 251.0. R2(15) is 0.50 g/ml or more and 0.65 g/ml or less.
The rewetting value of the absorbent material is 3 g or less. The absorbent according to claim 1.
The adhesive is applied without a pattern. The absorbent according to claim 1.
A sanitary product comprising the absorbent material described in claim 1 .
The sanitary product according to claim 8 , comprising the absorbent body, a liquid-permeable upper sheet formed on the upper part of the absorbent body, and a waterproof back sheet formed on the lower part of the absorbent body.
The sanitary product according to claim 8 , which can be used as a diaper, sanitary napkin, or incontinence pad.

Description

[Cross-reference of related applications] This application claims priority rights based on Korean Patent Application No. 10-2022-0153919 dated November 16, 2022, and Korean Patent Application No. 10-2023-0159226 dated November 16, 2023, and all content disclosed in the documents of said Korean Patent Applications is incorporated herein by reference. This invention relates to an absorbent material and sanitary product containing the same, which can appropriately fix superabsorbent polymer particles within the absorbent material and sanitary product without using pulp, thereby contributing to the thinning of the absorbent material and sanitary product, and exhibiting excellent shape retention even after moisture absorption. Generally, various types of diapers, sanitary napkins, and incontinence pads contain an absorbent material with superabsorbent polymer particles. However, such absorbent materials typically consist mainly of these superabsorbent polymer particles, and pulp is used to maintain the shape of the absorbent material and the sanitary product while appropriately fixing these particles. However, the presence of this pulp made it difficult to slim down and thin absorbent materials and sanitary products, resulting in problems such as sweat accumulating between the user's skin and the product, leading to poor wearing comfort. Furthermore, the need to use large quantities of this pulp, which is mainly obtained from wood, goes against the recent trend of environmental protection and has become one of the main reasons for the increased manufacturing cost of the absorbent layers and sanitary products. Therefore, many attempts have been made to reduce the amount of pulp used in the absorbent layer and sanitary products, or to provide sanitary products such as so-called pulpless diapers that do not use pulp at all. However, excessively reducing the amount of pulp used resulted in multiple tears in the absorbent material due to low binding strength. Furthermore, the superabsorbent polymer particles were not properly fixed within the absorbent material and sanitary products, causing the absorbent material to shift to specific areas during transportation, resulting in uneven absorption performance and preventing the sanitary products from maintaining their shape properly. On the other hand, conventional sanitary products that do not use pulp, such as pulpless diapers, primarily use liquid adhesive compositions to fix the superabsorbent polymer particles. This aims to achieve thinner and slimmer absorbents and sanitary products, as well as lower unit costs due to the absence of pulp. However, in conventional sanitary products, excessive use of adhesive can lead to disadvantages such as reduced performance of the superabsorbent polymer particles and the absorbent material itself, or process problems due to adhesive migration. Conversely, reducing the amount of adhesive used resulted in disadvantages such as uneven absorption performance due to particle migration, as the superabsorbent polymer particles were not properly fixed within the absorbent material and sanitary product. Furthermore, the problem of the absorbent material and sanitary product not maintaining their shape after moisture absorption by the superabsorbent polymer particles remains unresolved. Due to these problems with conventional technologies, there is a continuing need for technological development in absorbent materials and sanitary products that can appropriately fix superabsorbent polymer particles within the absorbent material and sanitary product without performance degradation, while either eliminating or significantly reducing the use of fluff pulp, and exhibiting excellent shape retention even after moisture absorption. Figure 1 shows a cross-section of the absorbent body of Examples 1 to 3, illustrating an absorbent body in which a first nonwoven fabric 1, an adhesive layer 3, a first coating layer of superabsorbent resin 4, a first coating layer of adhesive 5, a second coating layer of superabsorbent resin 6, a second coating layer of adhesive 7, a third coating layer of superabsorbent resin 8, an adhesive layer 9, and a second nonwoven fabric 2 are sequentially laminated. Layers 4 to 8 are superabsorbent resin layers. The terms used herein are used solely to describe exemplary embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as “includes,” “equip,” or “have” are intended to specify the existence of implemented features, steps, components, or combinations thereof, and should not be understood to presuppose the existence or possibility of adding one or more other features, steps, components, or combinations thereof. The present invention can be modified in various ways and may take many forms; therefore, specific embodiments are illustrated and described in detail below. However, this should not b