JPS6323224A - Leader tape - Google Patents

Abstract

PURPOSE:To obtain a leader tape having excellent wear resistance, antistatic property, non-tackiness and ray transmittivity by using the hydrolyzate of an alkoxysilane having an epoxy group in the molecule, the hydrolyzate of an alkoxysilane having an amino group and/or imino group in the molecule and white pigment as essential components for a protective layer. CONSTITUTION:The protective layer of the laminate of polyester films consist of A, the hydrolyzate of the alkoxysilane which is expressed by the formula XmSi(OR)4-m (X is an org. group contg. an epoxy group, OR is an alkoxy group of 1-6C, m is 1 or 2) and has the epoxy group in the molecule, B, the hydrolyzate of the alkoxysilane which is expressed by the formula YnSi(OR)4-n (Y is an org. group contg. an amino group and/or imino group, OR is an alkoxy group of 1-6C, n is 1 or 2) and has the amino group and/or imino group in the molecule and C, the white pigment as the essential components. The solid content ratios by weight of A:B:C thereof are specified to 10-50:90-10:1-9. The wear resistance, antistatic property and non-tackiness of the above- mentioned tape are thereby improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a leader tape or trailer tape (hereinafter collectively referred to as a leader tape) connected before and after a magnetic recording medium.

[Prior Art] Conventionally, leader tapes include (1) films made of polyethylene terephthalate, vinyl chloride, etc., mixed with antistatic agents;

(2) Laminated film in which an antistatic agent layer containing a white pigment is laminated on a base film (for example, JP-A-47-38007, JP-A-49-40504, JP-A-49-67603)
(3) A laminated film in which a base film is laminated with an antistatic layer as the first layer and a layer mainly composed of a white pigment and a binder as the second layer (for example, JP-A-53-32002) )It has been known.

[Problems to be Solved by the Invention] However, the above conventional leader tape has the following problems.

The film in item (1) has insufficient antistatic properties,
As the static electricity disappears over time, it becomes difficult to remove the static electricity, and the adhering dirt and dust dislocates onto the surface of the magnetic layer and the magnetic head, causing dropouts and decreased output. Furthermore, since the abrasion resistance of the film surface was insufficient, the film surface was abraded during running of the tape and generated dust.

When the film described in item (2) satisfies the antistatic properties, adhesion occurs, and if the amount of white pigment added to prevent adhesion is increased, the light transmittance required for end detection may decrease or the film surface may become sticky. There were problems such as dust generation due to lack of white pigment due to lack of abrasion resistance.

The film described in item (3) has no adhesion even if it satisfies the antistatic property, and there is no practical problem in terms of light transmittance.However, dust is generated from the tape itself due to insufficient abrasion resistance on the film surface. There were also problems such as increased manufacturing costs due to the two-layer structure.

It is an object of the present invention to solve these problems and provide a leader tape that has excellent abrasion resistance, antistatic properties, non-adhesive properties, and light transmittance.

[Means for Solving the Problems] The present invention provides a laminate in which a protective layer is laminated on at least one side of a polyester film, in which the protective layer has the following formula: A, general formula XmSi (OR) (wherein
-m is an organic group containing an epoxy group; OR is an alkoxy group having 1 to 6 carbon atoms; 1m is a hydrolyzate of an alkoxysilane having an epoxy group in the molecule; B; general formula Y Si ( OR) (However,
Yn 4-n is an organic group containing an amino group and/or an imino group.

OR is an alkoxy group having 1 to 6 carbon atoms, n is 1 or 2)
A hydrolyzate of an alkoxysilane having an amino group and/or an imino group in the molecule represented by, which has a C1 white pigment as its main component, and has a solid content weight ratio of A:B:C of 10 to 50:90 to 10. :1 to 9.

The polyester film in the present invention has a mechanical strength of 1
A biaxially stretched polyethylene terephthalate film is suitable from the viewpoint of dimensional stability, but is not limited thereto.

The thickness of the film is usually preferably 10 to 50 microns.

If the film thickness is less than 10μ, the tape will easily break at the clamp part that fixes the leader tape, and if it exceeds 50μ, the difference in thickness at the connection part with the magnetic recording part will be too large. This has disadvantages such as the shape of the connection part being transferred.

Although not particularly required in the present invention, the film surface may be subjected to acid or alkali treatment, corona discharge treatment, ultraviolet irradiation treatment, etc. to activate the surface and improve the adhesion of the protective layer.

The protective layer of the present invention is mainly composed of three components A, B, and C.

The first component A constituting the protective layer has the general formula XmSi
(OR> (However, X is an organic group containing an epoxy group -m, OR is an alkoxy group having 1 to 6 carbon atoms 1m
is a hydrolyzate of an alkoxysilane having an epoxy group in the molecule represented by 1 or 2), and the hydrolyzate A is a compound 2 represented by the above general formula, for example, CHcuCHCHpOCH2CH2CH2S!
(OCH3) This is a prepolymer obtained by hydrolyzing the alkoxy groups of one or a mixture of three alkoxysilanes in a dilute acidic aqueous solution such as a dilute aqueous hydrochloric acid solution or a dilute aqueous sulfuric acid solution.

The second component B has the general formula YnSi (OR> (where Y is an organic group containing an amino group and/or an imino group, and OR is a carbon number of 1 to
The alkoxy group in 6, ")" is composed of a hydrolyzate of an alkoxysilane having an amino group and/or imino group in the molecule represented by 1 or 2>, and is an organic group containing the above amino group and/or imino group. Generally, those having 2 to 10 carbon atoms are preferably used.The hydrolyzate B is a compound represented by the above general formula, for example, H2N CH2Cl-bNHcH2cH2cH2s!
(OCH3) 3HriNCH2CHCH2CH Ku N1
cHps i (OCJ5) 3H2N CH2
CH2-N HCH2CH2cl-12S! (
After hydrolyzing the alkoxy groups of one or a mixture of alkoxysilanes such as 0CH2>2δH3 with a dilute acidic aqueous solution in the same manner as above, a volatile organic acid is added to cause a neutralization reaction with amino groups and imino groups. It is a prepolymer stabilized in the form of an organic acid salt.

Volatile organic acids include formic acid, acetic acid, propionic acid,
Organic acids with relatively low boiling points, such as butyric acid, are preferred. This existence II
The amount added is preferably in the range of 0.5 to 10 moles, more preferably in the range of 1.0 to 5.0 moles, per 1 mole of the total amino groups and/or imino groups of the silane.

If it is less than 0.5 mole, the epoxy group reacts with the amino group or imino group, resulting in gelation, which tends to shorten the coating composition, while if it is more than 10 mole, the coating film tends to be insufficiently cured.

The third component C is a white pigment, and the white pigment C includes titanium oxide, zinc oxide, calcium carbonate, silicon dioxide, zinc sulfide, and antimony oxide.

White lead (2PbCO3・Pb(OH)2>, aluminum oxide, barium sulfate, barium carbonate, talc (3M
C]0.4Si02.H2O>, clay (Aff203
・2S i 02・2H20). The particle diameter of the white pigment is preferably in the range of 0.3 to 10μ, more preferably in the range of 0.5 to 5μ. Particle size is 0.3
If it is smaller than μ, the surface of the protective layer tends to stick. On the other hand, 1
If it is larger than 0μ, the unevenness on the surface of the protective layer becomes thick (and the surface becomes rough).

The blending ratio of components A, B, and C constituting the main components of the protective layer is such that the solid content weight ratio of each is A:B:C=10 to 50:9.
It is necessary to set it as the range of 0-50:1-9. When the solid content it ratio of A is less than 10, the wear resistance of the protective layer decreases. If the solid content weight ratio of B is less than 50, the antistatic properties of the protective layer will decrease. If the weight ratio of the white pigment is less than 1, the surface of the protective layer tends to become sticky, while if it is more than 10, dust is likely to be generated due to lack of the white pigment.

The thickness of the protective layer is preferably in the range of 5 to 10 microns, more preferably in the range of 1 to 5 microns. If the thickness is less than 0.5μ, wear resistance will be insufficient. On the other hand, if it is thicker than 10 μm, the protective layer tends to generate dust.

Next, a method for manufacturing the leader tape of the present invention will be explained.

The hydrolyzate A of an alkoxylan having an epoxy group in the molecule constituting the protective layer is prepared by reacting one molecule of water per alkoxy group with a dilute acidic aqueous solution, such as N
/1000-N/100 dilute aqueous hydrochloric acid solution is added to hydrolyze the alkoxy groups to obtain a prepolymer.

Hydrolyzate B of alkoxysilane having an amino group and/or imino group in the molecule is obtained by adding a dilute acidic aqueous solution in the same proportion as above to hydrolyze the alkoxy group, and then
An organic acid such as formic acid or acetic acid is added to form a salt of an amino group, an imino group and an organic acid. Next, after dissolving the above A and B in an organic solvent and dispersing the white pigment, a curing agent, curing catalyst, additives, etc. are added as necessary, and diluted roughly with a solvent to a concentration of 5 to 40% by weight. % is applied to at least one side of a polyester film by a conventional roll coater or spray method, and then cured by heating or by UV, β, or γ radiation.

The thus obtained laminated film is slit (eg, 3 inches wide for VH8) and connected to the front and rear of the Ia recording medium to form a leader tape.

[Effects of invention According to the present invention, the following effects can be obtained.

(2) Since the protective layer has excellent abrasion resistance, the surface of the leader tape does not become abraded and generate dust.

(2) Since the amount of white pigment added is small, light transmittance is good, tape end detection is good, and there is no dust generation due to lack of pigment.

■Since it has good antistatic properties, there is no accumulation of static electricity, so there is no adhesion of dirt or dust.

[Method for Measuring Characteristics and Evaluating Effects] Methods for measuring characteristic values and evaluating effects of the present invention are as follows.

■, Wear-resistant white pigment loss vibration type abrasion tester (JIS, LO823), load 20 (
100 and 500 reciprocations on the protective layer surface with l.

It was rubbed back and forth 1000 times, and the occurrence of scratches and the presence or absence of missing white pigment were visually determined.

(2) Easy slippage The protective layer surfaces of the films were overlaid in accordance with ASTM D-1894, and the static friction coefficient μ5. The dynamic friction coefficient μd was measured.

■, antistatic, manufactured by Kawaguchi Electric Co., Ltd., electrostatic copy line analyzer, MODEL-
After the surface of the protective layer of the film is charged with corona discharge at +6 KV for 10 seconds using 3P-428, the dark decay half-life of the surface potential is measured.

■、Light transmittance Measured according to JIS 6714.

■ Shun cut the sticky diblocking layer film into a 3-inch wide tape, wrapped this tape around a 36 mm diameter glass tube with a load of 3-, and left it at 45°C and 80% RH for 24 hours. The interlayer adhesion between the tapes was visually inspected.

[Example] The present invention will be explained based on examples.

Example 1 The following protective layer paint was applied to one side of a 30 μ thick biaxially stretched polyester film (“Lumirror” manufactured by Toshiku Co., Ltd.) using a roll coater so that the solid content was 3 g/m2. Then, it was dried at 140° C. for 2 minutes to obtain a laminated film for a leader tape.

Table 1 shows the measurement results of the laminated film.

Protective layer paint A component: 54 parts by weight of N/100-hydrochloric acid was added to 236 parts by weight of γ-glycidoxypropyltrimethoxysilane (5H6040 manufactured by Toray Silicone Co., Ltd.) to hydrolyze the alkoxy groups to give a concentration of 57 290 parts by weight of component A was obtained.

Component B 2N-β(aminoethyl)γ-aminopropyltrimethoxysilane (KBM-60 manufactured by Shin-Etsu Chemical Co., Ltd.)
3> 110 parts by weight of N/100-hydrochloric acid was added to a mixture of 450 parts by weight of ethyl alcohol and 450 parts by weight of ethyl alcohol to hydrolyze alkoxy groups, and then 600 parts by weight of acetic acid was added to a colander to prepare B with a solid content concentration of 25% by weight. 1610 parts by weight of the components were obtained.

After mixing component A and 8 components, 29 weights of calcium carbonate (particle size 1 μm to 5 μm) were added and mixed and dispersed, and 60 parts by weight of isopropyl alcohol was added to obtain a paint having a concentration of 30% by weight.

Comparative Example 1 In Example 1, 8 parts by weight of calcium carbonate (particle size 1 to 5 μm) was added to component A and mixed and dispersed, and 280 parts by weight of isopropyl alcohol was added to obtain a paint with a concentration of 30% by weight. A laminated film having a solid content coating amount of 39/Tr12 was obtained in the same manner as in Example 1. Table 1 shows the measurement results of the laminated film.

Comparative Example 2 The following protective layer paint was applied to one side of a 30 μ thick biaxially stretched polyester film using a roll coater so that the solid content coating amount was 3 g/Tr12, dried at 140°C for 2 minutes, and laminated. Got the film. Table 1 shows the evaluation results of the laminated film.

Paint antistatic agent for protective layer (manufactured by Sanyo Chemical Industries, Ltd., Chemistat 62)
00. 14 parts by weight of calcium carbonate (particle size 1 to 5 μm) and 373 parts by weight of water were added to 600 parts by weight (concentration: 47% by weight) and mixed and dispersed to obtain a paint having a concentration of 30% by weight.

As is clear from Table 1, the leader tape of Example 1, which satisfies the two requirements of the present invention, is excellent in abrasion resistance, antistatic properties, non-adhesive properties, etc.

Claims (1)

[Claims] A laminate in which a protective layer is laminated on at least one side of a polyester film, wherein the protective layer has A, general formula XmSi(OR)_4_-_m (where X
is an organic group containing an epoxy group, OR is an alkoxy group having 1 to 6 carbon atoms, and m is 1 or 2) - a hydrolyzate of an alkoxysilane having an epoxy group in the molecule; )＿４＿－＿＿n(However,
Y is an organic group containing an amino group and/or an imino group, O
R is an alkoxy group having 1 to 6 carbon atoms, n is 1 or 2); C, a hydrolyzate of an alkoxysilane having an amino group and/or an imino group in the molecule; C, a white pigment as a main component; A leader tape characterized in that the solid content weight ratio of A:B:C is 10-50:90-10:1-9.