JP2002146274A - Primer and pressure-sensitive asdhesive tape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a water-based primer that has water resistance and high adhesion properties though the primer is a water-based primer, and provide a pressure-sensitive adhesive tape using the primer. SOLUTION: The primer, which is laminated on a film substrate comprising as a base material PVC(polyvinyl chloride) or EEA(ethylene/ethyl acrylate), comprises 100 pts.wt. MMA(methyl methacrylate)-grafted natural rubber (in terms of dry solids content) and 25-400 pts.wt. NBR(acrylonitrile/butadiene rubber) (in terms of dry solids content).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a primer to be laminated before laminating a pressure-sensitive adhesive on a substrate of an electric insulating pressure-sensitive adhesive tape for winding an electric wire used in electric equipment and automobiles, and an adhesive using the primer. The present invention relates to a tape, and more particularly to a primer when the substrate is made of soft PVC (polyvinyl chloride) or EEA (ethylene ethyl acrylate) and an adhesive tape using the primer.

[0002]

2. Description of the Related Art Conventionally, as a primer laminated on a sheet-like base material of PVC or EEA, an MMA-grafted natural rubber (a material obtained by grafting MMA (methyl methacrylate) on a natural rubber) is used. When the primer is applied to the material, the primer is diluted with a solvent (toluene, MEK (methyl ethyl ketone), ethyl acetate, or the like). That is, a solvent-based primer that is diluted with a solvent is conventionally used as the primer.

[0003]

However, in the solvent system, the solvent is ignited by the static electricity of the base material during primer coating, particularly at the time of unwinding or contact with the roll of the base material, which may cause a fire. There was a problem that. In addition, when a worker sucks or absorbs a solvent that is volatilized during the production of an adhesive tape, the solvent has the property of dissolving fat. The cause was a failure.

Therefore, it is conceivable to convert a solvent-based primer into a water-based primer (a primer that melts with water). In the case of simply using a water-based primer, the primer may be a substrate and / or an adhesive. There was a problem that it did not adhere to the agent. As a means for solving this problem, the present applicant has disclosed an aqueous primer whose elastomer is mainly composed of MMA (methyl methacrylate) -grafted natural rubber and NBR (acrylonitrile butadiene rubber) (Japanese Patent Application No. 2000-120722). reference).
This primer is an effective invention because it has the effect of adhering the base material and the adhesive to some extent.

[0005] However, even with this primer, it has not been possible to meet the demand for high adhesion.

Accordingly, it is an object of the present invention to provide a water-based primer having high adhesion even with a water-based primer and an adhesive tape using the primer.

[0007]

That is, the primer according to the present invention is made of PVC (polyvinyl chloride) or EEA.
(Ethyl ethyl acrylate) A primer to be laminated on a film base material containing as a main component, the elastomer of the primer is 100 parts by weight of MMA (methyl methacrylate) -grafted natural rubber (in terms of dry), NBR (acrylonitrile butadiene rubber) 25 to 400 parts by weight (in terms of dry), and the elastomer is characterized in that 3 to 40 parts by weight of tackifier (in terms of dry) are blended with 100 parts by weight (in terms of dry) of the elastomer. Things.

In another aspect of the invention, a PVC (polyvinyl chloride) or EEA (ethylene ethyl acrylate) film substrate, an adhesive layer laminated on one or both sides of the film substrate, A pressure-sensitive adhesive tape, comprising the primer laminated between a material and the pressure-sensitive adhesive layer.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the tackifier is blended with the primer in order to impart high adhesion to the water-based primer and to achieve adhesion between the base material and the adhesive. As the tackifier, a conventionally known natural resin type and synthetic resin type used for the adhesive can be appropriately selected. In the natural resin system, rosin (gum system, tall system, wood system), (hydrogenation, disproportionation, polymerization, esterification, metal chloride) rosin derivative, terpene resin system (α-pinene, β-
Pinene, others), terpene phenols, others (dammar, copearl, shellac) and the like. Synthetic resins include petroleum resins (aliphatic, aromatic, alicyclic, copolymer, coumarone indene resins), phenolic resins (alkylphenol resins, modified phenolic resins), and xylene resins (xylene resins, Modified xylene resin).

In the present invention, if the mixing ratio of the tackifier is too small, the adhesion to the substrate cannot be increased, and if it is too large, the adhesion to the pressure-sensitive adhesive decreases. For 100 parts by weight of elastomer,
The amount is preferably 3 to 40 parts by weight, more preferably 10 to 30 parts by weight.

In the present invention, MMA is used as a primer.
The reason for blending the (methyl methacrylate) -grafted natural rubber is to maintain the adhesion between the primer and the adhesive. As the MMA-grafted natural rubber, a conventionally known MMA-grafted natural rubber can be appropriately selected and used, and MG-23 (MMA content: 23%), MG-30
(MMA content 30%), MG-40 (MMA content 4
0%), MG-49 (49% MMA content), MG-5
0 (MMA content 50%).

In the present invention, NBR is used as a primer.
(Acrylonitrile butadiene rubber) is blended because it is uniformly dispersed even when diluted with water and has adhesiveness to a PVC-based substrate or an EEA-based substrate, and is further contained in a soft PVC substrate. This is also to prevent migration of the plasticizer. If the compounding ratio of the NBR is too large, the adhesion to the pressure-sensitive adhesive is reduced, and if it is too small, the adhesion to the substrate is reduced. 25 to 400 parts by weight (in terms of dry) is good relative to parts by weight,
Preferably, the amount is 30 to 300 parts by weight (calculated as dry).

As the NBR, a conventionally known NBR can be appropriately selected and employed, and a low nitrile type (nitrile content of 24% or less) and a medium nitrile type (nitrile content of 2% or less) are used.
5-30%), medium and high nitrile type (nitrile content 3)
1-35%), high nitrile type (nitrile content 36)
~ 42%), extra high nitrile type (nitrile content 43)
% Or more).

The concentration of the primer when it is applied is suitably 5 to 20% in view of the coating properties and the coating amount.

[0015] The primer may optionally contain a wetting agent. Examples of the wetting agent include an anionic surfactant, a nonionic surfactant, a cationic surfactant, and an amphoteric surfactant. The addition amount (in terms of dry) is preferably 2 to 15 parts by weight based on 100 parts by weight of the main agent.

When the primer according to the present invention is used for an adhesive tape, it is laminated on one side or both sides of a PVC-based or EEA-based film substrate. The adhesive tape is completed by laminating the adhesive on the primer. As the pressure-sensitive adhesive, a commonly used pressure-sensitive adhesive can be appropriately used, and examples thereof include a rubber-based pressure-sensitive adhesive and an acrylic pressure-sensitive adhesive. The thickness of the adhesive is suitably from 5 to 40 μm.

The manufacturing process of the pressure-sensitive adhesive tape will be described.
The primer having the above composition is diluted with water and dispersed on one side of the substrate, and then coated and dried. An adhesive is applied to the dried primer and then wound up to complete the adhesive tape. When winding up the completed pressure-sensitive adhesive tape, a release agent may be laminated on the back surface of the base material or a release sheet may be laminated on the pressure-sensitive adhesive as necessary. When the pressure-sensitive adhesive tape is applied to both surfaces of the substrate, the step of applying the primer and the pressure-sensitive adhesive may be performed on the back surface.

[0018]

EXAMPLES Examples of the present invention will be described below with reference to Table 1.
Will be described in more detail with reference to and comparison with a comparative example. The numerical values of the compositions in Table 1 are parts by weight (dry).
And the number of times the characteristic value is dropped is as follows. "Adhesion between the primer and the substrate" means that the primer surface coated on the substrate is made of a plastic eraser (PE-01 manufactured by Tombow Pencil Co., Ltd.).
A) Rubbing (pressing 5 kg / cm ² , moving speed 15 m /
Minutes) and the number of times before dropping out, and it is necessary that it does not drop off even after 20 times. In Table 1, “> 30” indicates that the sample did not fall off even after 30 times. "The adhesion between the primer and the adhesive" refers to the number of times that the adhesive surfaces of the two adhesive tapes are adhered to each other and then peeled off until the adhesive comes off. is necessary. "Adhesion between the base material and the adhesive after immersion in water" refers to a method in which the adhesive tape with the surface of the adhesive exposed is immersed in water for 2 days, and 30 seconds after the water attached to the adhesive surface is wiped off. The number of times until the pressure-sensitive adhesive falls off after the pressure-sensitive adhesive surfaces are pasted to each other is checked. It is necessary that the pressure-sensitive adhesive does not fall off even after 20 times.

[0019]

[Table 1]

The primer in Example 1 was composed of 75 parts by weight of MMA-grafted natural rubber, 25 parts by weight of NBR, and a terpene resin having a softening point of 115 ° C. as a tackifier.
5 parts by weight were blended. The pressure-sensitive adhesive tape used for the measurement of the characteristic value used a soft PVC as a base material, used the primer of the above-mentioned combination as a primer, and used a natural rubber-based pressure-sensitive adhesive. The other examples and comparative examples described below are the same as the present example unless otherwise specified.

Comparative Example 2, Example 2 and Comparative Example 3 in which the compounding ratio of the terpene resin as the tackifier mixed in the primer was changed (the compounding ratio of the terpene resin was 2, 15, 6).
Compared with 0), Comparative Example 2 in which the compounding ratio of the terpene resin was small had poor adhesion between the primer and the base material, and Comparative Example 3 in which the compounding ratio of the terpene resin was large had poor adhesiveness between the primer and the adhesive. .

Comparative Example 1, Example 1, Example 2, Example 3, and Comparative Example 4 in Table 1 in which the blending ratio of NBR blended in the primer was changed (the blending ratio of NBR was 5, 25, 50, 7
5 and 95 parts by weight), Comparative Example 1 having too little NBR had poor adhesion between the primer and the substrate, and Comparative Example 4 having too much NBR had poor adhesion between the primer and the adhesive.

[0023]

According to the present invention, there is provided a primer laminated on a film base material mainly composed of PVC (polyvinyl chloride) or EEA (ethylene ethyl acrylate), wherein the elastomer of the primer is MMA (methyl methacrylate).
100 parts by weight of grafted natural rubber (dry conversion), NB
R (acrylonitrile butadiene rubber) 25 to 400
Parts by weight (in terms of dry), and the elastomer is characterized in that 3 to 40 parts by weight of tackifier (in terms of dry) are blended with respect to 100 parts by weight (in terms of dry) of the elastomer. High adhesion could be provided even with the above primer.

Further, another invention relates to a PVC (polyvinyl chloride) or EEA (ethylene ethyl acrylate) film substrate, a pressure-sensitive adhesive layer laminated on one or both sides of the film substrate, Adhesive tape characterized by interposing the primer laminated between the adhesive layer, even with an adhesive tape using a water-based primer thereby adhesive tape using a solvent-based primer High adhesion could be provided while having the water resistance.

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Shigeo Kawasaki 2-13-1, Dai, Kamakura-shi, Kanagawa F-term in Toyo Kagaku Co., Ltd. (Reference) 4J004 AA04 AA05 AB01 CA04 CA05 CC02 CD04 EA06 FA05 4J038 BA232 CM032 CP011 CP081 CR012 DA002 GA01 GA10 KA02 MA06 MA08 MA09 MA10 NA12 NA21 PA18 PB07 PB09 PC02 PC08

Claims (2)

[Claims] 1. A primer laminated on a film base material mainly composed of PVC (polyvinyl chloride) or EEA (ethylene ethyl acrylate), wherein the elastomer of the primer is MMA (methyl methacrylate) -grafted natural rubber 100. Parts by weight (dry conversion), 25 to 400 parts by weight of NBR (acrylonitrile butadiene rubber)
y conversion), and the elastomer includes the elastomer 10
Tackifier 3-4 for 0 parts by weight (dry conversion)
A primer characterized by containing 0 parts by weight (in dry terms). 2. A PVC (polyvinyl chloride) or EEA (ethylene ethyl acrylate) film substrate, a pressure-sensitive adhesive layer laminated on one or both sides of the film substrate, and between the film substrate and the pressure-sensitive adhesive layer. An adhesive tape comprising the primer according to claim 1 laminated on the adhesive tape.