JP3019973B2 - Easy peeling adhesive composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to adhesiveness, peelability,
It relates to a pressure-sensitive adhesive composition that has film-forming properties and is useful as an adhesive material for temporary fixing that can be easily peeled off as necessary after bonding.
I do .

[0002]

2. Description of the Related Art Conventionally, decorative pieces such as tiles have been used to make up the outer wall surface of a concrete building. Pasting of this kind of decorative strips has long been carried out after the construction of concrete walls,
Although it was performed manually by a tile craftsman or the like, in recent years, due to a demand for labor saving, a decorative piece is temporarily held in advance on a surface of a form member for forming a concrete wall, and the decorative piece is placed by pouring concrete. Is fixed to the wall surface, the decorative piece is left on the surface of the concrete wall, and the mold member is removed, so that the removal of the decorative piece is completed at the same time as the removal from the mold. (For example, Japanese Patent Publication No. Sho 62-2)
No. 4589).

[0003] Further, a mold member used in this type of construction method uses a synthetic resin foam material such as styrene foam,
A concave portion for fitting and holding the decorative piece is formed on the molding die surface of the mold frame member, and the decorative piece is temporarily held by press-fitting into the concave portion, and the back surface of the decorative piece, that is, the side fixed to the concrete. Is protruded from the molding die surface of the mold frame member in many cases.

[0004]

The conventional method of temporarily holding a decorative piece on a mold member is to press-fit the decorative piece into a concave portion of the mold member and to form the decorative piece of foam resin. Since the decorative piece is held by elasticity, it can be applied by the hammering at the time of assembling the form member, transporting, and pouring the concrete, and inserting the vibrator for compacting the poured concrete. The pieces often peel off from the frame member, and therefore, there is a problem that much trouble is required to repair the missing portion of the decorative piece at the time of carrying in the frame member or after removing the mold.

As a method for solving such a problem, a method of using an adhesive, that is, a method of interposing an adhesive between the front side surface of the decorative piece and the bottom surface of the concave portion of the mold member, and holding the decorative piece by the adhesive force. However, in order to reuse a mold member made of a synthetic resin foam such as styrene foam,
It is necessary to remove the decorative piece from the form member without damaging the form member at the time of removal from the mold. It is necessary that the adhesive remaining on the formwork member or the decorative piece surface later be easily peeled off.However, with the conventional adhesive, if the adhesiveness is strong, the adhesive remaining on the decorative piece surface may be removed. There was no one that could meet all of these conditions because it was not easy.

In the conventional method, a so-called toro-rotation in which a toro (mainly a cement paste component in the concrete) enters between the surface of the decorative piece and the concave portion in which the toro is fitted at the time of casting concrete after assembling the form member. There is a problem that it is apt to occur, and a lot of trouble is required for finishing after demolding.

The present invention has been made in view of such a conventional problem,
The work of assembling and compacting the formwork members and compacting the concrete and holding the decorative pieces without falling off even under strong wind and rain conditions during the work, and without damaging the formwork members when removing the formwork members Adhesion that can be easily removed from the surface of the decorative piece after removal from the surface, and can be easily removed from the surface of the decorative piece by washing with water, and can also be used as a film forming agent for protecting the glass surface. It is intended to provide an agent composition and the composition.

[0008]

SUMMARY OF THE INVENTION The features of the present invention for solving the conventional problems as described above and achieving the intended purpose are as follows.
Highly polymerized polyvinyl alcohol having a polymerization degree of 1000 to 2000
And low polymerization polyvinyl alcohol having a polymerization degree of 200 to 700
And polyvinyl alcohol consisting of two types
Agent A consisting of a solution to which water is added,
The adhesive composition is easily peelable from the agent B comprising an anate .

Incidentally, polyvinyl alcohol is used in the above high polymerization.
5 to 20 parts by weight of polyvinyl alcohol (parts by weight, hereinafter the same)
And low-polymerized polyvinyl alcohol is from 1 to 20 parts.
High-polymerization, low-polymerization polyvinyl alcohol
15 to 25 parts of polyvinyl alcohol, dextrin
Mix 1-5 parts, 70-80 parts of water and an appropriate amount of a dispersing aid
Agent A and Agent B consisting of polyisocyanate to Agent A
3 to 10% by weight in combination with the dispersing aid
And it is preferable to use 1 to 5 parts of propylene glycol.
New

[0010]

The present invention comprises a polymer compound having an OH group formed by hydrolyzing vinyl acetate, for example, an agent A having polyvinyl alcohol, and a polyisocyanate.
When a crosslinking agent is mixed with the agent B, a cross-linking reaction occurs, and as this proceeds, a rubbery pressure-sensitive adhesive having tackiness is obtained. Also, since CO ₂ gas is generated with the crosslinking reaction,
Air bubbles are dispersed in the pressure-sensitive adhesive to form a foam.

The pressure-sensitive adhesive has tackiness in the state of holding water, but becomes a porous material in a dry state because the water contained in the agent A disappears by evaporation, and loses its own tackiness. Then, when water is given after drying once, the water permeates into the porous material without returning to the tackiness, and swells and becomes cloudy.

Accordingly, when this pressure-sensitive adhesive is applied to, for example, the surface of a glass plate, it forms a transparent film and adheres to the glass surface, similarly to a conventional polyvinyl alcohol-based adhesive. Then, even after drying, the adhered state of the film is maintained, but the film itself loses tackiness. The major difference from conventional adhesives is that when the film is no longer needed, the film is swelled and turbid by impregnating the film with water, and the adhesive force to the surface of the glass plate is lost. Is to come off.

Further, the viscosity of polyvinyl alcohol varies depending on the degree of polymerization.
000) and low polymerization degree (200-700) by adjusting the mixing ratio. When a large number of low polymerization degrees are blended, the formed film (film) can be thickened without increasing the viscosity.

The polyisocyanate is added to make the pressure-sensitive adhesive rubbery, to promote the formation of a film, and to increase the releasability when the pressure-sensitive adhesive is removed.

[0015] Propylene glycol and dextrin act to assist the crosslinking reaction, propylene glycol acts as a dispersing aid, and dextrin acts to increase the adhesive strength and acts as a coating substance when forming a coating. .

In addition, cellulose as a third additive substance,
Natural synthetic rubbers, leather, organic compounds such as paper, earth and stone,
Inorganic compounds such as clay and slag are exemplified.

Further, when the pressure-sensitive adhesive obtained by mixing the above-mentioned A agent and B agent is used as a temporary fixing agent for temporarily holding the decorative piece on the mold member, for example, After being applied in the concave portion, the decorative piece is fitted into the concave portion, so that when it is interposed between the inner surface of the concave portion and the decorative piece, it becomes rubbery as the crosslinking reaction progresses and the adhesive strength increases, and the adhesive force increases. The falling off of the makeup pieces is prevented.

On the other hand, since the pressure-sensitive adhesive layer is adhered in the form of a film without air between the bottom surface of the concave portion of the mold member and the surface of the decorative piece, the adhesive state is maintained even by a vacuum force. Then, from the assembly of the form member to the placement of concrete, for example, for several days to several tens of days, the central portion of the adhesive film that does not come into contact with fresh air is difficult to dry, and the adhesiveness and vacuum property are maintained. You.

Further, the rubberized pressure-sensitive adhesive is not water-soluble and does not lose its adhesive strength even when it is exposed to fresh water. Therefore,
The pieces do not fall off even in the rain.

On the other hand, the holding by the adhesive is based on the adhesiveness and the vacuum property, and therefore is not very strong unlike the adhesive, and is peeled off from the side of the adhesive film after the completion of the crosslinking reaction to reduce the vacuum. By removing it, it is possible to easily peel it off, and it is possible to remove the mold member made of a synthetic resin foam without damaging it with the decorative piece remaining on the concrete wall surface.

Further, even if the adhesive remains on the surface of the decorative piece, the adhesive is naturally dried once and then spontaneously peels off with water so that it can be easily dropped.

By interposing an adhesive between the bottom surface of the decorative piece fitting concave portion and the decorative piece surface over the entire surface of the decorative piece, penetration of the toro from the outer peripheral edge of the decorative piece is prevented, and the toro rotation is prevented. Disappears.

[0023]

Embodiments of the present invention will now be described with reference to the drawings.

Polyvinyl alcohol (PVA) is used as a polymer compound having an OH group formed by hydrolyzing vinyl acetate in the agent A, and difesylmethane diisocyanate (MTL) is used as an agent B as a crosslinking control component. (NC
(25-30% as O) is used.

The following range is preferable for the compounding of the agent A. Polyvinyl alcohol High polymer (polymerization degree 1000 to 2000) 5 to 20 parts (parts by weight, the same applies hereinafter) Low polymer (polymerization degree 200 to 700) 1 to 20 parts Propylene glycol 1 to 5 parts Dextrin 1 to 5 parts Preservative (Paraoxybenzoic acid ester) Appropriate amount Perfume (limonene-based perfume) Appropriate amount Purified water 70-80 parts 100 parts in total amount In addition, polyvinyl alcohol is 15 in total for high and low polymer.
~ 25 parts is preferred. If the amount is less than 15 parts, the concentration of the film-forming component in the solution is low, so it takes time to form and dry the film, and it is difficult to achieve a predetermined effect.If the amount exceeds 25 parts, the viscosity of the solution increases, Disturbance in handling,
In some situations, it is necessary to further dilute the entire solution with water, which significantly reduces workability.

If the amount of the high-polymerized polyvinyl alcohol is too small, drying and cross-linking of the formed film is slow and the strength is small. If the amount is too large, the entire solution gels and the properties of the formed film deteriorate. Thus, the desired effect is not exhibited.

Propylene glycol acts as a dispersing aid, and an amount necessary for dispersing polyvinyl alcohol in water is used. The preferred range is 1 to
5 parts. If the amount is less than 1 part, the effect of improving the dispersibility cannot be obtained, and if it exceeds 5 parts, the elastomer of the formed film increases, and the proper peel strength cannot be maintained.

Dextrin is used as a tackifier, and if it is used in an amount as large as 5 parts or more, the tackiness is too strong, and the releasability of the mold member at the time of demolding becomes poor. On the other hand, if the amount is less than 1 part, the effect of enhancing the adhesiveness cannot be obtained.

The water is preferably purified water having no impurities.
~ 80 parts is good. If the amount is less than 70 parts, the viscosity of the entire solution is increased, so that the solution must be further diluted with water to adjust the viscosity. If the amount exceeds 80 parts, the viscosity of the solution is low, it takes time to dry the film, and the strength is also reduced. As a result, it is necessary to perform re-adjustment such as newly adding PVA to the solution and dissolving it. Become.

The preservative is used for quality stability. The preservative and fragrance are not particularly limited, and an appropriate amount of a conventional one may be used as needed.

[0031] Formulation Examples of A agent and the B agent, (1) W% A agent 90 to 97% B agent 3-10% total 100 (2) W% A dosage ninety-two to eighty% B agent 3-10% first Three substances 5-10% total 100 (3) W% A agent 60-70% Water 10-35% B agent 5-10% total 100 (4) W% A agent 40-50% B agent 5-10% water 20-35% Third substance 5-15% Total 100 (5) W% A agent 25-45% Third substance 10-20% Water 5-30% Agent B 10-20% Total 100 (6) W% A Agent 50-70% Third substance 15-30% Water 5-30% Agent B 5-20% Total 100.

The amount of each of the agents B is 3 to 10 based on the agent A.
% By weight is preferred. If it is less than 3% by weight, the crosslinking property is poor and the rubber does not form. Use in excess of 10% by weight is costly.

As the third substance, organic substances such as cellulose, natural or synthetic rubbers, leather and paper, mud and stones,
Inorganic substances such as clay and slag are included.

The pressure-sensitive adhesive composition of the present invention comprises a component A and a component B. The component A is prepared by adding an appropriate amount of propylene glycol to PVA, further adding water, dextrin, and a preservative, heating, and dissolving with stirring. Allow to cool, add fragrance and produce.

The agent B is prepared by reacting 4,4'-diphenylmethanediamine with carbonyl to form 4,4'-diphenylmethanecarbamic acid chloride.
Produce diphenylmethane diisocyanate.

The A agent and the B agent are mixed at a predetermined ratio when used. The mixing method is not particularly limited. After mixing, it is preferable to use it immediately by applying it to the surface of a decorative piece.

The pressure-sensitive adhesive of the present invention can be easily peeled off by applying water, and has a certain tackiness (adhesion) up to that time, so that it can be used in various fields as long as it can be washed with water.

A particularly preferable method is to use the pressure-sensitive adhesive in a concave portion for fitting a decorative piece formed on the surface of a formwork member for forming a decorative surface of civil engineering or building such as a concrete structure. A method of temporarily holding a decorative piece in a formwork member for decorative surface molding of civil engineering or building, wherein the decorative piece is temporarily held on the surface of the formwork member for decorative surface formation by being interposed between the decorative member and the decorative piece.

At this time, the form member for decorative surface molding is not particularly limited, but is preferably made of synthetic resin foam. Among them, a polypropylene resin foam as disclosed in Japanese Patent Application Nos. 9-42007 and 9-41967 is preferable.

Further, the decorative piece is not particularly limited. Preferred are a tile, a glass plate, a ceramic plate, a metal plate and the like.

The assembly of the decorative surface forming member temporarily holding the decorative pieces by this method and the construction of the concrete decorative wall surface are as follows.
It may be carried out by the method disclosed in Japanese Patent Application No. 9-42007 or Japanese Patent Application No. 9-41967.

Since the amount of the adhesive used varies depending on the application,
Although not limited to, it is necessary that the amount is interposed over the entire surface of the decorative piece, at least according to the material of the mold member and the uneven shape of the surface of the tile-shaped decorative piece, and at most within the concave portion. The amount must not overflow from

As described above, by interposing the adhesive over the entire surface of the decorative piece to prevent the so-called toro-rotation in which the toro invades concrete between the decorative piece surface and the bottom of the concave portion when the concrete is poured. Finishing after removal from the mold is facilitated.

Test Example A decorative piece fitting concave portion 2 was provided on the surface of a foamed polypropylene mold frame member 1 shown in FIG. 1 in a number of 68 per mold, and an adhesive 3 was applied in each concave portion 2 with a brush. Thereafter, a decorative piece 4 made of a tile (a small tile for PC board) was fitted into each. As shown in FIG. 2, five mold members (total number of decorative pieces: 340) are set as one group, and six test zones A to F are arranged as shown in FIG. 3, and shown in FIG. In this way, concrete 6 is cast in the space between the inner mold members 5 in the space between the inner mold members 5 to remove the decorative pieces during the construction process, remove the mold members, and remove the adhesive from the tile surface. I saw the situation.

It should be noted that the state of falling of the decorative pieces is as follows: during the installation of the form member, that is, during the assembling work of the form member temporarily holding the decorative piece as a concrete form, after the number of decorative pieces dropped, after rainfall and watering, That is, there is rainfall after the embedding of the form member, furthermore, the number of pieces of cosmetic pieces dropped after artificially watering, after using the hammer, that is, after the rainwater sprinkling, nails on the back of the form member with the hammer when assembling the formwork. The number of pieces of decorative pieces dropped when hitting to the extent that hitting was assumed, after concrete casting, that is, concrete casting work, compaction from inside concrete by high-frequency vibrator, and backside of formwork member by hitting with wooden hammer The number of pieces of cosmetic pieces dropped out during the compacting work from the soil and the demolding work after the concrete was solidified was counted.

The pressure-sensitive adhesive conditions in each section were as shown in Table 1.

Here, AM936 and SQ906R are conventional adhesives, and ST1 is the adhesive of the present invention. The numerical value of each g / m ^{2 in} the table indicates each coating amount.

Here, AM936 and SQ906 are both water-soluble adhesives mainly composed of an acrylic resin manufactured by NSC, AM936 is a water-soluble emulgilone, and SQ906 is a solvent-based one. is there.

The product of the present invention had the following composition.

Agent A Polyvinyl alcohol (manufactured by Shin-Etsu Chemical Co., Ltd.) High polymer (average degree of polymerization 1800) 15 parts Low polymer (average polymerization degree 500) 2 parts Propylene glycol (manufactured by Showa Denko KK) 2 parts Dextrin (Nissei Chemical Co., Ltd.) 2 parts Purified water (distilled water) 80 parts Paraoxybenzoate (Ueno Pharmaceutical Co., Ltd.) 0.2 parts Limonene-based fragrance (Miyasaka Perfume Co., Ltd.) 0.1 parts Two parts of diphenylmethane diisocyanate (produced by Nippon Polyurethane Industry Co., Ltd.) (B agent) were mixed and used immediately before use.

The agent A was prepared by adding propylene glycol to PVA in advance, mixing, adding dextrin and p-hydroxybenzoic acid, heating and dissolving, cooling, and adding a fragrance.

Test Results Table 2 shows the situation of the cosmetic pieces falling off during the operation. Table 3 shows the mold breakage status during demolding.

In each of the sections A, B, C, and D using the conventional products, it was difficult to remove the mold in all the sections, and most of the mold members were damaged so that they could not be reused.

On the other hand, in the E and F sections of the product of the present invention, demolding was easy, and all of the products could be demolded without being damaged. The state of removal of the pressure-sensitive adhesive after release from the mold was as shown in Table 4.

In the sections A, B, C, and D using the conventional products, it was difficult to remove them. On the other hand, in the sections E and F of the product of the present invention, they could be easily removed by washing with water.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a state in which a decorative piece is held on a mold member according to the present invention.

FIG. 2 is a front view showing an arrangement of a form member in one test section in a test example.

FIG. 3 is a plan view showing the arrangement of all test sections in the above.

FIG. 4 is a cross-sectional view showing the concrete casting state of the above.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Form member 2 Concave part 3 Adhesive 4 Decorative piece 5 Inner form 6 Concrete

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshiaki Koizumi 4-3-1-10 Hanahata, Adachi-ku, Tokyo Co., Ltd. (72) Inventor Koichi Yoshida 4-3-1-10 Hanahata, Adachi-ku, Tokyo Co., Ltd. (56) References JP-A-49-96077 (JP, A) JP-B-62-24589 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) C09J 175 / 04 C08G 18/62 C08L 75/04

Claims (4)

(57) [Claims] 1. A highly polymerized polystyrene having a degree of polymerization of 1,000 to 2,000.
Nyl alcohol and low-polymerized poly with a degree of polymerization of 200 to 700
Polyvinyl alcohol consisting of two types: vinyl alcohol
A consisting of a solution containing water as the main ingredient and water
And an easily peelable pressure-sensitive adhesive composition comprising a polyisocyanate-B agent . 2. The high-polymerized polyvinyl alcohol is a polyvinyl alcohol.
5 to 20 parts of vinyl alcohol (parts by weight, the same applies hereinafter);
Low-polymerized polyvinyl alcohol consisting of 1 to 20 parts
The pressure-sensitive adhesive composition according to claim 1, which is easily peelable. 3. Highly or lowly polymerized polyvinyl alcohol
15 to 25 parts of polyvinyl alcohol
Mix 1-5 parts of phosphorus, 70-80 parts of water and an appropriate amount of a dispersing agent.
Agent A combined with Agent B comprising polyisocyanate
3. The composition according to claim 1, wherein the content is 3 to 10% by weight.
3. The easily peelable pressure-sensitive adhesive composition according to 2. 4. Propylene glycol as a dispersing aid
The easily peelable pressure-sensitive adhesive composition according to claim 3, wherein the pressure-sensitive adhesive composition is used in an amount of from 5 to 5 parts.