JPH04239578A - Adsorption sheet - Google Patents

Abstract

PURPOSE:To provide an adsorption sheet for fixing a car accessory such as aromatic agent to an inner trim of automobile, having not too large adhesive force to facilitate the peeling from an adherend and enabling easy transfer and re-pasting of the car accessory without staining the adherend after peeling. CONSTITUTION:The objective adsorption sheet is produced by coating a surface of a nonwoven fabric substrate with a rubbery or acrylic tacky adhesive layer and impregnating the other surface with a gelatinous silicone rubber layer produced by cross-linking a composition composed of a polyorganosiloxane having Si-bonded vinyl group and a polyorganohydrogen siloxane having Si- bonded hydrogen atom in the presence of an addition reaction catalyst.

Description

[Detailed description of the invention]

0001

[Industrial Application Fields] The present invention is applicable to aroma deodorants (hereinafter referred to as fragrances), illumination lights, mood lamps, cigarette cases, paper clips, ash cases, pen pockets, coin holders, cassette cases, cigarette holders, and drinks. We attach and fix car accessories such as stands, swing mascots, compasses (magnetic discs), message stickers, thermometers, hygrometers, table clocks, and digital tachometers to automobile interior materials such as instrument panels, center consoles, and door trims. The present invention also relates to an adsorption sheet for easy peeling.

0002

[Prior technology] There are car accessories such as those mentioned above, but among them, air fresheners meet the needs of young people and women who want to enjoy a scented life. Lately, it has been used a lot, even to the effect of erasing it. Most of these car air fresheners are liquid types, and are housed in plastic containers.General users can attach an adhesive sheet to the bottom of the container and attach it to the desired location on the interior of the car. The adhesive sheet may be pre-adhered to the air freshener container or may be separated, and the same applies to other car accessories such as cigarette holders, paper clips, thermometers, and mood lamps.

[0003] As the pressure-sensitive adhesive sheet, a support such as a nonwoven fabric, cloth, plastic film, rubber sheet, foam, etc. is coated on both sides with a rubber-based or acrylic-based pressure-sensitive adhesive layer.

[0004] The above-mentioned rubber adhesive is made of natural rubber, IR, S
Elastomers such as BR, IIR, recycled rubber, and styrene-isoprene-styrene copolymers are combined with tackifiers such as rosin, rosin derivatives, terpene resins, terpene phenol resins, petroleum resins, coumaron indene resins, and liquid polybutene. Add plasticizers such as mineral oil, lanolin, liquid polyisoprene, liquid polyacrylate, fillers such as zinc white, titanium white, calcium carbonate, clay, pigments, and anti-aging agents such as rubber-based antioxidants and metal dithiocarbamates. It is what it is.

[0005] Acrylic adhesives mainly contain acrylic esters (C4 to C12) to impart adhesiveness, and acrylic acid, methacrylic acid, acrylamide, and vinyl acetate to impart cohesive force and adhesive strength.・The main component is a copolymer of reactive monomers such as styrene, and if necessary, crosslinking agents such as epoxy resins, isocyanates, and melamine resins can be added to provide even more cohesive strength.

However, most of these pressure-sensitive adhesives are designed for permanent adhesion and have strong adhesive strength, resulting in the following disadvantages. In other words, ■ Commercially available car accessories are made of polyurethane foam to cope with car vibrations.
Many products use adhesive sheets with foam supports such as foamed polyethylene, foamed butyl rubber, or foamed chloroprene rubber, and in these cases, if you try to peel off the adhesive once it has been affixed, the foam will break. It becomes impossible to reapply and use it. ■Indoor temperatures in cars reach 80 to 90 degrees Celsius in the summer, but rubber and acrylic adhesives have low heat resistance, so if you try to replace the air freshener with a new one after using it for one to two months, the adhesive will It deteriorates with age and becomes stuck to car interior materials, which cannot be removed even by cleaning with water, neutral detergent, organic solvents, etc. In addition, this automobile interior material is made from plastic materials such as polyvinyl chloride, ABS resin, polypropylene, and polyurethane, and has poor chemical and solvent resistance, and the surface turns white when washed with neutral detergents or organic solvents. , the original condition cannot be restored. There were other inconveniences. Furthermore, the above-mentioned conventional pressure-sensitive adhesive sheets do not adhere to silicone resin-treated surfaces, so they have the disadvantage that fragrances and other car accessories cannot be attached and fixed thereto.

[0007]

[Problems to be Solved by the Invention] In view of the above-mentioned circumstances, the present invention provides an adsorption sheet for fixing car accessories such as air fresheners to automobile interior materials, which
The adhesive strength is not stronger than necessary and it can be easily peeled off from the surface to which it is attached, the car accessory can be moved and reattached easily, the surface to which it is to be peeled does not become dirty after being peeled off, and it is treated with silicone resin. This was done in an attempt to provide something effective for surfaces as well.

[0008]

[Means for Solving the Problems] The present invention has solved the above-mentioned problems by forming a rubber-based or acrylic adhesive layer on one side of a nonwoven fabric support and silicone on the other side. A composition consisting of a polyorganosiloxane having a vinyl group bonded to an atom and a polyorganohydrogensiloxane having a hydrogen atom bonded to a silicon atom,
The gist of the present invention is an adsorption sheet formed by impregnating a layer of gel-like silicone rubber (hereinafter referred to as silicone gel) that is cross-linked in the presence of an addition reaction catalyst. In the present invention, this sheet is referred to as a suction sheet because it is similar to a suction cup in that it is resistant to dust and can be moved and reapplied any number of times.

The present invention will be explained in detail below. The nonwoven fabric used in the adsorption sheet of the present invention functions as a support for the adsorption sheet, and is impregnated with silicone gel, which is liquid when uncrosslinked, and is used for anchoring. This nonwoven fabric uses cellulose fibers, polyester fibers, polyethylene fibers, polypropylene fibers, polyvinyl alcohol fibers, nylon fibers, aramid fibers, glass fibers, etc., using thermal bonding, needle punching, spunless, melt blowing, and spunbonding methods. The thickness is selected from the range of 10 μm to 1 mm, but if it is too thin, it will lack the strength as a support, and if it is too thick, the silicone gel will penetrate into it. 100 μm because the amount is large and expensive silicone gel is used more than necessary.
It is preferable to set it as the range of 300 micrometers.

The rubber or acrylic adhesive used in the adsorption sheet of the present invention has the composition described above, but it is preferable to use an acrylic adhesive commonly used in commercially available double-sided adhesive tapes. An example of synthesis of an acrylic adhesive is acrylic acid alkyl ester (C4 to C
12) A comonomer mixture of 50 to 80 parts by weight of vinyl acetate or short chain acrylic acid alkyl ester or methacrylic acid alkyl ester (C1 to C4), and 1 to 6 parts by weight of maleic anhydride. is 0.5 based on the total monomer amount under N2 gas flow.
In the presence of ~3% by weight of a radical initiator (benzoyl peroxide or azobisisobutyronitrile), in a single or mixed solvent of toluene, benzene, and ethyl acetate (based on a total monomer amount of 20 to 40 parts by weight, 60 to 60 parts by weight)
Polymerization is carried out at 0 to 70°C, and after the polymerization, 0.1 to 3 equivalents of polyol, polyamine, or polyisocyanate are added to the maleic anhydride in the solution and crosslinked to obtain an adhesive with excellent heat resistance.

[0011] The step of forming the acrylic adhesive layer on one side of the nonwoven fabric by coating is preferably carried out prior to the step of forming the silicone gel layer. This is because silicone gel, which is liquid when uncrosslinked, has a low viscosity, so if it is coated on a nonwoven fabric, it will not be supported and will drip down, but the acrylic adhesive layer formed first acts as a sealant when coated with silicone gel. This is because it plays the role of

Coating with the acrylic adhesive is carried out using a coating machine such as a knife coater, doctor roll coater, comma roll coater, three-roll reverse roll coater, Meyer bar coater, or gravure coater. The dry film thickness of acrylic adhesive is 20-30
The thickness may be on the order of μm, and it is preferable to use a comma roll coater to coat this film thickness region stably and accurately. If the acrylic adhesive has a high viscosity of several hundred P or more, it will not penetrate into the nonwoven fabric base material, and as shown in Figure 1, which shows a cross section of an example of the adsorption sheet of the present invention, a uniform acrylic adhesive will be applied to the surface of the nonwoven fabric. A pressure-sensitive adhesive layer 4 is formed. The coating machine is a coater/laminator equipped with a coating head, drying oven, and laminator, and if the surface of the nonwoven fabric is coated with an adhesive and a release paper is laminated in the post-process, it can be rolled up and stored. As this release paper, it is preferable to use a so-called silicone release paper obtained by treating a paper base material such as kraft paper, glassine paper, or parchment paper with silicone.

[0013] The silicone gel used in the present invention is produced by adding a composition consisting of a polyorganosiloxane having a vinyl group bonded to a silicon atom and a polyorganohydrogensiloxane having a hydrogen atom bonded to a silicon atom to a catalyst for an addition reaction. A gel-like cured product is obtained by a crosslinking reaction in the presence of polyorganosiloxane. The proportion of hydrogen atoms (hydrogen groups) in the entire side groups (including terminal groups) of hydrogensiloxane is preferably 0.1 to 4.0 mol%, more preferably 0.2 to 2.0 mol% on average.
It is 0 mol%. The reason for this is that when the proportion of the vinyl group and the hydrogen atom is less than 0.1 mol%, it is difficult to form a gel, and when it exceeds 4.0 mol%, the gel formed becomes too hard and cannot perform its function. Because it will come. Further, the vinyl group/hydrogen atom ratio is usually preferably 0.8.
-3, more preferably 0.9-2. The reason for this is that if this ratio is too large, the heat resistance of the silicone gel obtained will decrease due to the residual vinyl groups, and if this ratio is too small, foaming will occur easily during gel formation.

[0014] The remaining side groups excluding the vinyl group of the polyorganosiloxane having a vinyl group bonded to a silicon atom used in the present invention, and excluding the hydrogen atom of the polyorganohydrogensiloxane having a hydrogen atom bonding to a silicon atom, are used in the present invention. The remaining side groups are substituted or unsubstituted monovalent hydrocarbon groups excluding aliphatic unsaturated groups, such as alkyl groups such as methyl, ethyl, and propyl groups, aryl groups such as phenyl, and β- unsubstituted hydrocarbon groups such as aralkyl groups such as phenylethyl groups and β-phenylpropyl groups, and
Examples include substituted hydrocarbon groups such as chloromethyl group, cyanoethyl group, and 3,3,3-trifluoropropyl group, but from the viewpoint of ease of synthesis and the heat resistance and physical properties of the resulting gel, methyl Most preferred are groups.

Further, the polyorganosiloxane having a vinyl group bonded to a silicon atom and the polyorganohydrogensiloxane having a hydrogen atom bonded to a silicon atom used in the present invention have a viscosity of 100 to 1 at 25°C.
A range of 00,000 cP is preferred, and a range of 300 to 5,000 cP is more preferred. The reason for this is that if the viscosity is too high, workability and bubble removal will be poor, and if the viscosity is too low, it will flow easily and the physical properties after reaction will be poor.

[0016] Furthermore, the addition reaction catalyst used in the present invention is
This is for causing an addition reaction between the vinyl group bonded to the silicon atom in the above polyorganosiloxane and the hydrogen atom bonded to the silicon atom in the polyorganohydrogensiloxane. , platinum-based compounds such as coordination compounds of chloroplatinic acid and olefins or vinylsiloxane, triphenylphosphine palladium, triphenylphosphine rhodium, and other known compounds can be used. The blending ratio of this addition reaction catalyst is 0.1 to 100 p to the total amount of the polyorganosiloxane and polyorganohydrogensiloxane.
It may be selected within the range of pm, preferably within the range of 3 to 20 ppm. The reason for this is that if the proportion of the addition reaction catalyst is too high, discoloration due to thermal deterioration and an increase in cost will occur, and if the proportion is too low, curing will likely be inhibited.

The adsorption sheet of the present invention has a rubber or acrylic adhesive layer 4 formed on one side of a nonwoven fabric support 2, and the above-mentioned silicone gel on the other side, as the cross section is shown in FIG. The layer 3 is formed by impregnation, and as shown in the cross section of FIG. 2, another support 7 is attached to the rubber or acrylic adhesive layer 4 formed on the nonwoven fabric support 2. In addition, it is also optional to form a rubber-based or acrylic-based adhesive layer 4 on the other surface of the support 7. This support body 7 is used for the purpose of giving flexibility to the uneven surface of the automobile interior material subjected to grain roll processing and for the purpose of alleviating vibrations of the automobile.
It is preferable to use foams such as foamed polyurethane, foamed polyethylene, foamed butyl rubber, and foamed chloroprene rubber.
The thickness is preferably selected from the range of 0.5 to 2 mm.

In FIGS. 1 and 2, release paper 5 and release paper 6 are used to protect the adsorption sheet of the present invention when not in use, and the release paper 6 on the rubber or acrylic adhesive layer 4 side So-called silicone release paper, which is made by coating kraft paper, glassine paper, parchment paper, etc. commonly used in general adhesive tapes with linear polymer siloxane and partially crosslinking to form an elastic film, may be used. silicone gel layer 3
As a result of various studies by the present inventors, the release paper 5 on the side has been found to be sufficient if a plastic film such as polyethylene film, polypropylene film, or polyester film is used alone.

[0019]

Effects of the Invention The adsorption sheet of the present invention has a rubber or acrylic adhesive layer formed on one side of the adsorption sheet and a silicone gel layer on the other side. The agent layer surface is strongly adhered to car accessories such as air freshener containers, and the silicone gel layer surface is adsorbed to the surface of automobile interior materials. By using the adsorption sheet of the present invention, the accessory can be fixed to the surface of the automobile interior material and can be easily peeled off without leaving any adhesive residue on the same surface, so the accessory can be moved and fixed to a different position at will. or when it is no longer needed, it can be thrown away without staining the surface of the interior material.

[0020]

[Examples] The present invention will be explained in detail with reference to Examples below. Polyester fiber/rayon fiber mixed nonwoven fabric with a thickness of 200 μm when surface pressure is 40 gf/cm2, TK450
-A (manufactured by Mitsubishi Rayon Co., Ltd., trade name) as a support, an acrylic adhesive with a viscosity of 20,000 cP, Arontack A-2408H (manufactured by Toagosei Chemical Industry Co., Ltd.),
Coat (trade name) on one side of the support using a comma roll coater and dry to a dry film thickness of 25 μm.
Form an adhesive layer, release paper, and binder sheet 80HB-
018 (manufactured by Fujimori Kogyo Co., Ltd., trade name) was laminated onto the adhesive layer.

[0021] Next, an addition reaction was performed using a composition consisting of a polyorganosiloxane having a vinyl group bonded to a silicon atom and a polyorganohydrogensiloxane having a hydrogen atom bonded to a silicon atom, and having a viscosity of 1,000 cP. A liquid silicone rubber, KE-1052A/B (manufactured by Shin-Etsu Chemical Co., Ltd., trade name), which becomes a silicone gel when subjected to a crosslinking reaction in the presence of a catalyst, and a similar liquid silicone rubber, X-32-796 ( (manufactured by Shin-Etsu Chemical Co., Ltd., trade name) in a weight ratio of 10:90, was impregnated and coated on the untreated surface of the nonwoven fabric support using a comma roll coater, and heated at 80°C x 5 A silicone gel layer is formed on the surface of this silicone gel layer to a thickness of 25 μm after drying under conditions of 10 minutes to form a silicone gel layer so that the total thickness of the adhesive sheet including the acrylic adhesive film thickness (excluding the release paper) is 270 μm. Laminated with Lumirror S type polyester film.

When the 180° peel adhesion strength of this adsorption sheet was measured using a polyvinyl chloride sheet as the object to be adhered, it was 180 gf/cm on the acrylic adhesive layer side and 50 gf/cm on the silicone gel layer side. 90
Although it was left in an environment of 4 hours at 80 degrees Celsius and 24 hours at 80 degrees Celsius, there was almost no change in peel adhesive strength.

[0023] This adsorption sheet 11 was punched to a diameter of 30 mm and was placed on the bottom surface 12 of a commercially available air freshener container having an oval shape of 65 mm x 90 mm, a height of 60 mm, and a total weight of 220 g including the contents. 3, and actually pasted it on the top of the instrument panel of a Nissan Sunny (Model E-B11) manufactured by Nissan Motor Co., Ltd., and drove it on general roads in the Kanto region for 3 months during the summer (June to August). After 1,000 km of driving, there were no abnormalities such as falling off, and when I peeled it off after 3 months, it was able to be peeled off without leaving any adhesive on the instrument panel surface, and it was easy to paste it to other places. Ta.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining an example of the configuration of an adsorption sheet of the present invention using a cross section thereof.

FIG. 2 is a diagram for explaining another example of the structure of the adsorption sheet of the present invention using a cross section thereof.

FIG. 3 is a perspective view of a fragrance container with an adsorption sheet attached thereto, in an example of the present invention.

[Explanation of symbols]

2　Nonwoven fabric 3 Silicone gel layer 4 Rubber or acrylic adhesive layer 5 Release paper 6 Release paper 7 Foam 11 Punched suction sheet 12 Bottom of air freshener container

Claims (1)

[Claims] Claim 1: A rubber or acrylic adhesive layer is formed on one side of a nonwoven fabric support, and a polyorganosiloxane having a vinyl group bonded to a silicon atom and a hydrogen atom bonded to a silicon atom are formed on the other side. 1. An adsorption sheet formed by impregnating a gel-like silicone rubber layer formed by crosslinking a composition comprising a polyorganohydrogensiloxane and a polyorganohydrogensiloxane in the presence of an addition reaction catalyst.