Body paper for carrier tape, paper tape made of body paper and electronic component packaging body

Abstract

The invention provides base paper for a carrier tape, a paper tape prepared from the base paper and an electronic component packaging body, the base paper for the carrier tape sequentially comprises a surface layer, a core layer and a bottom surface layer, the core layer is prepared from core layer pulp containing bleached chemimechanical pulp, cationic starch and PVA and contains borax added in a manner of dipping a sizing agent in a semi-dried state with the water content of the base paper being 6.0-12.0%, and the bottom surface layer is prepared from a surface layer, a surface layer and a bottom surface layer. According to the present invention, the borax can be cross-linked with the starch and the PVA linked to the fiber to form the network structure, such that the layering of the base paper is avoided, and the base paper is endowed with the low shrinkage rate and the low swelling rate so as to provide the square hole formed after the base paper is made into the paper tape with the excellent hole pattern squareness and the excellent size stability; after the paper tape is placed in the environment with the temperature of 60 DEG C and the environment with the temperature of 40 DEG C and the humidity of 90% RH for 24 h, the absolute values of the transverse (A0) and longitudinal (B0) dimensional change rates of the square holes are both smaller than or equal to 3%, and taking and using of the electronic elements contained in the square holes are prevented from being affected.

Description

Technical Field

[0001] The invention relates to the technical field of electronic component packaging consumables, in particular to a carrier tape base paper and a paper tape made therefrom, and an electronic component packaging body. Background Art

[0002] The carrier tape base paper generally includes a surface layer, a core layer, and a bottom layer or more. It uses bleached chemical wood pulp mixed pulp as the main production raw material, and is made into carrier tape base paper after papermaking and other steps. When in use, the carrier tape base paper needs to be cut into long strips of paper, and square holes for accommodating electronic components and round holes for pulling the paper tape are punched (through or not) at fixed intervals on the long strips to form a paper tape, and a cover tape is attached to form an electronic component packaging body, which is used in the packaging, storage, transportation and mounting of electronic components.

[0003] For example, the patent document with the publication number JP4422115B2 discloses a carrier paper for electronic chip components, which is made by forming square holes or recesses at predetermined intervals on a multi-layer paperboard with a wood pulp content of more than 50% based on the paper mass. The multi-layer paperboard has a surface layer, a middle layer and a back layer, and the thickness of the multi-layer paperboard is less than 1.10 mm, and is mainly made of bleached coniferous kraft pulp and hot-melt synthetic pulp. The proportion of synthetic pulp in the surface layer and the back layer is greater than 0wt% and less than 30wt% relative to the total mass of the pulp of the surface layer or the back layer, and the blending ratio of synthetic pulp is greater than 70wt% and less than 100wt% of the total mass of the pulp of the middle layer, and the wood pulp contained in the middle layer is only bleached coniferous kraft pulp. The carrier paper made of the above-mentioned multi-layer paperboard can suppress the fibrous fluff on the inner wall of the square hole or the recess even if it is thin.

[0004] However, the above-mentioned carrier paper still has the problems of high paper sheet shrinkage rate and high swelling rate. After the above-mentioned carrier paper is made into a paper tape, there are problems with the squareness and dimensional stability of the formed square holes. After the paper tape is placed in an environment with a temperature of 60°C and an environment with a temperature of 40°C and a humidity of 90%RH for 24 hours, the absolute values ​​of the transverse (A0) and longitudinal (B0) dimensional change rates of the square holes are both greater than 5%, resulting in jamming or horizontal material of electronic components, affecting the use of electronic components. Summary of the invention

[0005] In view of the shortcomings of the prior art described above, the object of the present invention is to provide a carrier base paper and a paper tape and electronic component packaging body made therefrom, so as to solve the problems of poor squareness and dimensional stability of the square holes of the paper tape caused by the high shrinkage rate and high swelling rate of the existing carrier base paper.

[0006] To achieve the above-mentioned purpose and other related purposes, the present invention provides a carrier base paper, which comprises a surface layer, a core layer and a bottom layer in sequence, wherein the core layer is made of a core layer pulp comprising bleached chemical mechanical pulp, cationic starch and PVA, and the carrier base paper contains borax added in the form of an impregnated sizing agent in a semi-dried state with a moisture content of 6.0~12.0%.

[0007] The square holes of the paper tape made of the carrier base paper (hereinafter referred to as base paper) of the above technical solution of the present application have excellent hole squareness and dimensional stability. The reasons are as follows: firstly, by using bleached chemical mechanical pulp with stiff fibers and not easy to swell in the core layer pulp, the base paper can be given low deformation, and cationic starch and PVA are added to the core layer pulp to form a connection between the polymer chain and the pulp fiber, thereby improving the fiber bonding force; secondly, by including borax in the base paper in a semi-dried state with a moisture content of 6.0-12.0% by impregnating the sizing agent, the borax and the bonding agent are bonded to each other. The cationic starch and PVA bound to the fibers are cross-linked to form a network structure, which further improves the bonding force between the fibers, improves the water and moisture resistance of the base paper, and makes the fiber spacing relatively fixed to form a stable, nearly rigid network structure, avoiding the stratification of the base paper, giving the base paper low shrinkage and low swelling rate; controlling the moisture content within the range of 6.0~12.0% is conducive to the penetration of the sizing agent into the base paper, increasing the cross-linking rate of borax with cationic starch and PVA, and preventing the problem that too high a moisture content reduces the penetration rate of the sizing agent into the base paper, and too low a moisture content reduces the fiber bonding strength.

[0008] Preferably, based on the total mass of the core layer pulp, the added amount of the cationic starch is 1.5-3.5wt%.

[0009] Preferably, based on the total mass of the core layer slurry, the added amount of the PVA is 0.5-2.5wt%.

[0010] Preferably, the core layer pulp also includes one or more of AKD, PAE and polyacrylamide retention aids to further improve the quality of the base paper.

[0011] More preferably, based on the total mass of the core layer pulp, the addition amount of AKD is 0.5-2.0wt%, the addition amount of PAE is 0.8-2.5wt%, and the addition amount of the polyacrylamide retention aid is 0.01-0.05wt%.

[0012] Preferably, the bleached chemimechanical pulp is selected from one or both of bleached coniferous wood chemimechanical pulp and bleached hardwood wood chemimechanical pulp.

[0013] Preferably, based on the total mass of the core layer pulp, the added amount of the bleached coniferous wood chemimechanical pulp is 43-46wt%, and the added amount of the bleached hardwood wood chemimechanical pulp is 43-46wt%.

[0014] Preferably, the sizing agent contains at least 0.50-2.5wt% borax. When the amount of borax added is less than 0.50wt%, the amount of borax that penetrates into the base paper is too small, and the stability of the cross-linked network formed by cross-linking with cationic starch and PVA is poor, which affects the shrinkage and swelling rate of the base paper; when the amount of borax added is greater than 2.5wt%, the shrinkage and swelling rate of the base paper are not much reduced compared to the addition amount of 2.5wt%, but excessive addition is not conducive to cost control.

[0015] Preferably, the sizing agent further comprises 0.1-0.3 wt % of fatty alcohol polyoxyethylene ether, which can be used as a penetrant to further improve the impregnation permeability of borax.

[0016] Preferably, the surface layer is made of surface layer pulp, and the bottom layer is made of bottom layer pulp, and both the surface layer pulp and the bottom layer pulp contain 80-90wt% of bleached coniferous wood pulp and 10-20wt% of bleached hardwood wood pulp.

[0017] The surface layer pulp and the bottom layer pulp use a high proportion of bleached coniferous pulp, which has longer pulp fibers and can give the base paper suitable surface strength. In addition, no other additives are added to the surface layer and the bottom layer except the above-mentioned wood pulp, so that the surface of the base paper has more gaps, which is convenient for the impregnation and penetration of the sizing agent.

[0018] More preferably, the surface layer pulp and the bottom layer pulp both contain 80 wt % of bleached coniferous wood pulp and 20 wt % of bleached hardwood wood pulp.

[0019] The carrier base paper is made by papermaking, pressing, first drying, surface sizing and second drying the core layer pulp, surface layer pulp and bottom layer pulp. After the first drying, the moisture content of the base paper is controlled within the range of 6.0-12.0%. The surface sizing is performed by impregnating the sizing agent, and the sizing agent contains borax.

[0020] The invention provides a paper tape, which is made of the base paper for carrier tape.

[0021] Preferably, the paper tape is formed with square holes for accommodating electronic components; after the paper tape is placed in an environment with a temperature of 60°C and an environment with a temperature of 40°C and a humidity of 90%RH for 24 hours, the absolute values ​​of the lateral (A0) and longitudinal (B0) dimensional change rates of the square holes are both ≤3%.

[0022] The present invention also provides an electronic component packaging body, comprising the paper tape.

[0023] As described above, the present invention has the following beneficial effects: by adding cationic starch and PVA to the core layer pulp and adding borax in the form of an impregnated sizing agent in a semi-dried state with a moisture content of 6.0-12.0% of the base paper, the borax can be cross-linked with the starch and PVA connected to the fibers to form a network structure, thereby avoiding the delamination of the base paper and giving the base paper a low shrinkage rate and a low swelling rate, so that the square holes formed after the base paper is made into a paper tape have excellent hole squareness and dimensional stability. After the formed paper tape is placed in an environment at a temperature of 60°C and an environment at a temperature of 40°C and a humidity of 90%RH for 24 hours, the absolute values ​​of the transverse (A0) and longitudinal (B0) dimensional change rates of the square holes are both ≤3%, thereby avoiding affecting the access to electronic components stored in the square holes. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Shown is a schematic diagram of the structure of the base paper for the carrier tape.

[0025] Description of the accompanying drawings: surface layer 1, core layer 2, bottom layer 3. DETAILED DESCRIPTION

[0026] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0027] It should be noted that the process equipment or devices not specifically specified in the following embodiments are all conventional equipment or devices in the art.

[0028] In addition, it should be understood that one or more method steps mentioned in the present invention do not exclude the existence of other method steps before or after the combination step or the insertion of other method steps between these explicitly mentioned steps, unless otherwise specified; and, unless otherwise specified, the numbering of each method step is only a convenient tool for identifying each method step, and is not intended to limit the order of arrangement of each method step or to define the scope of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the present invention without substantially changing the technical content.

[0029] The test method for the moisture content of the semi-dried base paper in the following embodiments of the present application is carried out according to the GB / T 462-2008 standard.

[0030] Example 1 like Figure 1As shown, Example 1 of the present application provides a carrier base paper, which includes a surface layer 1, a core layer 2 and a bottom layer 3 in sequence. The core layer is made of core layer pulp, the surface layer is made of surface layer pulp, and the bottom layer is made of bottom layer pulp. The carrier base paper contains borax added in the form of impregnation with a sizing agent in a semi-dried state with a moisture content of 10.0%. The base paper is made of surface layer pulp, core layer pulp and back layer pulp through papermaking, pressing, first drying, surface sizing and second drying. The sizing agent contains 1.0wt% borax and the balance is water.

[0031] Based on the total mass of the core layer pulp, the core layer pulp includes 46wt% bleached coniferous wood chemical mechanical pulp, 46wt% bleached hardwood chemical mechanical pulp, 1.5wt% AKD, 2.5wt% PAE, 0.05wt% polyacrylamide retention aid, 1.5wt% cationic starch, 1.5wt% PVA, and the balance is water.

[0032] Based on the total mass of the surface layer pulp, the surface layer pulp comprises 80wt% of bleached coniferous wood pulp and 20wt% of bleached broadleaf wood pulp.

[0033] Based on the total mass of the bottom layer pulp, the bottom layer pulp comprises 80wt% of bleached coniferous wood pulp and 20wt% of bleached broadleaf wood pulp.

[0034] The present application also provides a method for preparing the above-mentioned carrier paper, comprising the following steps: S1: Pulp preparation: Preparation of surface layer pulp: bleached coniferous wood pulp and bleached hardwood wood pulp are pulped and refined to prepare surface layer pulp, wherein the beating degree of the surface layer pulp is 25-28°SR; Preparation of core layer pulp: according to the above formula, bleached chemical mechanical pulp is pulped and refined, and then AKD, PAE, polyacrylamide retention aid, cationic starch and PVA are added, and the mixture is evenly mixed to form core layer pulp, and the beating degree of the core layer pulp is 20-22°SR; Preparation of bottom layer pulp: bleached coniferous wood pulp and bleached hardwood wood pulp are pulped and refined to prepare surface layer pulp, wherein the beating degree of the surface layer pulp is 25-28°SR; S2: first drying; The surface layer pulp, the core layer pulp and the bottom layer pulp are made into semi-dried base paper with a moisture content of 10.0% after papermaking, pressing and the first drying; S3: Surface sizing treatment: The semi-dried base paper with a moisture content of 10.0% is immersed in a sizing agent containing borax to perform surface sizing treatment; S4: Second drying and winding: The base paper treated with surface sizing is dried for the second time, calendered, rolled and packaged to form base paper for carrier tape.

[0035] Example 2 The difference between Example 2 and Example 1 is that the amount of borax added is different, specifically 1.5wt%, and the rest of the formula and preparation process are exactly the same.

[0036] Example 3 The difference between Example 3 and Example 1 is that the amount of borax added is different, specifically 2.0wt%, and the rest of the formula and preparation process are exactly the same.

[0037] Example 4 The difference between Example 4 and Example 1 is that the amount of borax added is different, specifically 2.5wt%, and the rest of the formula and preparation process are exactly the same.

[0038] Example 5 The difference between Example 5 and Example 1 is that when the surface sizing is applied, the moisture content of the base paper in the semi-dried state is different, specifically 6.0%, and the rest of the formula and preparation process are exactly the same.

[0039] Example 6 The difference between Example 6 and Example 1 is that when the surface sizing is applied, the moisture content of the base paper in the semi-dried state is different, specifically 12.0%, and the rest of the formula and preparation process are exactly the same.

[0040] Example 7 The difference between Example 7 and Example 1 is that the components of the sizing agent are different, the sizing agent further contains 0.1 wt % of fatty alcohol polyoxyethylene ether, and the rest of the formula and preparation process are exactly the same.

[0041] Example 8 The difference between Example 8 and Example 1 is that the components of the sizing agent are different, the sizing agent further contains 0.3 wt % of fatty alcohol polyoxyethylene ether, and the rest of the formula and preparation process are exactly the same.

[0042] Example 9 The difference between Example 9 and Example 1 is that the core layer pulp formula is different, the beating degrees of the surface layer pulp, core layer pulp and bottom layer pulp are different, and the other formulas and preparation processes are exactly the same.

[0043] Based on the total mass of the core layer pulp, the core layer pulp of this embodiment includes 43wt% bleached coniferous wood chemimechanical pulp, 43wt% bleached hardwood wood chemimechanical pulp, 0.5wt% AKD, 0.8wt% PAE, 0.01wt% polyacrylamide retention aid, 3.5wt% cationic starch, 0.5wt% PVA, and the balance is water.

[0044] The beating degree of the surface layer pulp is 23-25°SR; The beating degree of the core layer pulp is 20-23°SR; The beating degree of the bottom layer slurry is 23-25°SR.

[0045] Example 10 The difference between Example 10 and Example 1 is that the core layer pulp formula is different, the beating degree of the surface layer pulp, the core layer pulp and the bottom layer pulp is different, and the other formulas and preparation processes are exactly the same. Based on the total mass of the core layer pulp, the core layer pulp of this embodiment includes 45wt% bleached coniferous wood chemimechanical pulp, 45wt% bleached hardwood wood chemimechanical pulp, 2.0wt% AKD, 2.0wt% PAE, 0.025wt% polyacrylamide retention aid, 2.5wt% cationic starch, 2.5wt% PVA, and the balance is water.

[0046] The beating degree of the surface layer pulp is 25-28°SR; The beating degree of the core layer pulp is 22-25°SR; The beating degree of the bottom layer slurry is 25-28°SR.

[0047] Embodiment 11 The difference between Example 11 and Example 1 is that the core layer slurry formula is different, and the other formulas and preparation processes are exactly the same. Based on the total mass of the core layer pulp, the core layer pulp of this embodiment includes 45wt% bleached coniferous wood chemimechanical pulp, 45wt% bleached hardwood wood chemimechanical pulp, 2.5wt% cationic starch, 2.5wt% PVA, and the balance is water.

[0048] Example 12 The difference between Example 12 and Example 1 is that the core layer slurry formula is different, and the other formulas and preparation processes are exactly the same.

[0049] Based on the total mass of the core layer pulp, the core layer pulp of this embodiment includes 45wt% bleached coniferous wood chemimechanical pulp, 45wt% bleached hardwood wood chemimechanical pulp, 2.5wt% cationic starch, 2.5wt% PVA, 2.0wt% AKD, 2.0wt% PAE, and the balance is water.

[0050] Comparative Example 1 Comparative Example 1 used 60T base paper produced by Daio Paper Industries, Ltd.

[0051] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that when the surface sizing is applied, the moisture content of the base paper in a semi-dried state is relatively low, specifically 5.0%, and the rest of the formula and process are exactly the same.

[0052] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that when the surface sizing is applied, the moisture content of the base paper in a semi-dried state is relatively high, specifically 13.0%, and the rest of the formula and process are exactly the same.

[0053] Comparative Example 4 The difference between Comparative Example 4 and Example 1 is that the surface sizing step is eliminated, and the sizing agent is directly added to the core layer slurry, and the rest of the formula and process are exactly the same. In the process of making the core layer slurry of this comparative example, agglomerates adhere to the equipment, which affects the papermaking process.

[0054] Comparative Example 5 The difference between Comparative Example 5 and Example 1 is that the amount of borax added is different, specifically 0.4 wt %, and the rest of the formula and process are exactly the same.

[0055] Comparative Example 6 The difference between Comparative Example 6 and Example 1 is that the amount of borax added is different, specifically 3.0 wt %, and the rest of the formula and process are exactly the same.

[0056] The carrier paper of Examples 1 to 12 and Comparative Examples 1 to 6 is cut into long strips of paper with a width of 8 mm, and square holes for accommodating electronic components and round holes for pulling the paper tape forward are punched (through or not) at fixed intervals on the long strips of paper to form paper tapes.

[0057] The squareness and dimensional stability of the square holes formed by the paper tapes made of the carrier tape base paper of Examples 1 to 12 and Comparative Examples 1 to 6 were tested. The transverse (A0) and longitudinal (B0) dimensional change rates of the square holes were tested after each paper tape was placed in an environment with a temperature of 60°C and a temperature of 40°C and a humidity of 90%RH for 24 hours. The A0 and B0 dimensions were measured by the secondary element. The test results are shown in Table 1: Table 1. Test results of the squareness and dimensional stability of the square holes formed by the paper tapes of Examples 1 to 12 and Comparative Examples 1 to 6 As can be seen from Table 1, the carrier tape base paper of Examples 1 to 12 of the present application adds cationic starch and PVA to the core layer, and adds borax by impregnating the sizing agent when the base paper has a moisture content of 6.0 to 12.0% in a semi-dried state, so that the cationic starch, PVA and borax form a cross-linked network with the pulp fibers, thereby avoiding delamination of the base paper and giving the base paper a low shrinkage rate and a low swelling rate, so that the square holes formed after the base paper is made into paper tapes have excellent hole squareness and dimensional stability. After being placed in an environment at a temperature of 60°C and an environment at a temperature of 40°C and a humidity of 90%RH for 24 hours, the absolute values ​​of the transverse (A0) and longitudinal (B0) dimensional change rates of the square holes are both ≤3%, thereby avoiding affecting the access to the electronic components stored in the square holes.

[0058] By comparing the data of Example 1 and Comparative Example 1, it can be seen that the carrier paper obtained by adopting the technical solution of the present application has low shrinkage and low swelling rate. The square holes formed by the paper tape made of 60T base paper of Daio Paper Co., Ltd. in Example 1 have excellent hole squareness and dimensional stability. By comparing the data of Example 1, Comparative Example 2 and Comparative Example 3, it can be seen that when the surface is sizing, the moisture content of the base paper in the semi-dried state is too high or too low, which will lead to a larger dimensional change rate; by comparing the data of Example 1 and Comparative Example 4, it can be seen that if borax is directly added to the core layer pulp, cationic starch, PVA and borax will react first to form a cross-linked product (agglomerate) and adhere to the production equipment, causing operational obstacles, affecting the quality of the base paper, and failing to achieve the required low dimensional change rate; by comparing the data of Example 1, Comparative Example 5 and Comparative Example 6, it can be seen that when the amount of borax added is When it is less than 0.50wt%, the content of borax penetrating into the base paper is too small, and the cross-linking network formed by cross-linking with cationic starch and PVA is not strong enough. The absolute value of the transverse (A0) and longitudinal (B0) size change rate of the square holes of the paper tape made of the base paper is greater than 3%, but it is also better than conventional products, and the absolute value of the size change rate is less than 5%; when the addition amount of borax is greater than 2.5wt%, the absolute value of the transverse (A0) and longitudinal (B0) size change rate of the square holes of the paper tape made of the base paper does not change compared with 2.5wt%, and excessive addition is not conducive to cost control.

[0059] The above examples are for the purpose of illustrating the embodiments disclosed by the present invention and are not to be construed as limitations of the present invention. In addition, the various modifications listed herein and the variations of methods and compositions in the invention are obvious to those skilled in the art without departing from the scope and spirit of the present invention. Although the present invention has been specifically described in conjunction with various specific preferred embodiments of the present invention, it should be understood that the present invention should not be limited to these specific embodiments. In fact, various modifications obvious to those skilled in the art as described above to obtain the invention should be included within the scope of the present invention.

Claims

1. A base paper for a carrier tape, characterized in that: The invention comprises a surface layer (1), a core layer (2) and a bottom layer (3) in sequence, wherein the core layer is made of a core layer pulp comprising bleached chemical mechanical pulp, cationic starch and PVA, and the carrier base paper contains borax added in a form of impregnation with a sizing agent in a semi-dried state with a moisture content of 6.0 to 12.0%.

2. The carrier tape base paper according to claim 1, characterized in that: Based on the total mass of the core layer pulp, the added amount of the cationic starch is 1.5-3.5wt%.

3. The carrier tape base paper according to claim 2, characterized in that: Based on the total mass of the core layer slurry, the added amount of the PVA is 0.5-2.5wt%.

4. The carrier tape base paper according to claim 1, characterized in that: The bleached chemimechanical pulp is selected from one or both of bleached coniferous wood chemimechanical pulp and bleached hardwood wood chemimechanical pulp.

5. The carrier tape base paper according to claim 1, characterized in that: The sizing agent contains at least 0.50-2.5wt% of borax.

6. The carrier tape base paper according to claim 5, characterized in that: The sizing agent also contains 0.1-0.3 wt % of fatty alcohol polyoxyethylene ether.

7. The carrier tape base paper according to claim 1, characterized in that: The surface layer is made of surface layer pulp, and the bottom layer is made of bottom layer pulp. Both the surface layer pulp and the bottom layer pulp contain 80-90wt% of bleached coniferous wood pulp and 10-20wt% of bleached hardwood wood pulp.

8. A paper tape, characterized in that: It is made of the carrier paper as described in any one of claims 1 to 7.

9. The paper tape according to claim 8, characterized in that: The paper tape is formed with square holes for accommodating electronic components; after the paper tape is placed in an environment with a temperature of 60° C. and an environment with a temperature of 40° C. and a humidity of 90% RH for 24 hours, the absolute values ​​of the lateral and longitudinal dimensional change rates of the square holes are both ≤3%.

10. An electronic component package comprising the paper tape according to claim 8 or 9.

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