JPH10182204A - Peelable hot-melt composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a peelable hot-melt compsn. having a satisfactory adhesion to a decorative member, preventing contamination of the surface of the member by concrete milk, maintaining high work efficiency because of its proper melt viscosity and having flexibility and thermal stability by incorporating styrene- base thermoplastic elastomer. SOLUTION: This peelable hot-melt compsn. consists of 10-40wt.% styrene- base thermoplastic elastomer such as unsatd. rubber type styrene-butadiene- styrene and/or styrene-isoprene-styrene block copolymer, 5-60wt.% stickiness imparting resin such as hydrogenated petroleum resin, 10-70wt.% process oil such as paraffin oil and 10-40wt.% wax such as PE wax. A decorative member is fixed in a latticed form with the rear side downward and this hot metal- compsn. is melted and poured into the gaps and upper space. After solidification, the resultant decorative member unit is released from the form, the member is inverted and concrete is placed on the member.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot-melt composition having releasability, and more particularly to a hot-melt composition having releasability which is useful for fixing a decorative member in the production of a precast concrete with a decorative member. .

[0002]

2. Description of the Related Art Conventionally, as a method of attaching a decorative member such as a tile to a building concrete of a building, a method of attaching a decorative member with an adhesive at a construction site, a method of precasting concrete at a factory (hereinafter referred to as "PC concrete"). When manufacturing a concrete member, a so-called decorative member tensioning method is employed in which concrete is cast so that a part of the decorative member is embedded in the concrete body.

In the latter method, a decorative member unit consisting of several tens of decorative members is formed, the decorative member units are arranged in a predetermined size, and concrete is struck. The construction method of setting is known. At this time, a rubber base, styrofoam, or the like was used as a filler for keeping the gap between the decorative members, and a masking tape was used as a material for connecting the decorative members.

[0004] There are regular decorative members and irregular decorative members. In particular, there are various methods in the construction industry for manufacturing decorative member units from decorative members having different thicknesses and sizes, and at present, there is no uniform manufacturing method. Therefore, to make the depth of the decorative member part to be fitted into concrete the same for all decorative parts, the decorative members should be carefully arranged one by one and the level of the decorative member unit should be adjusted in some way. You need to do the work.

Furthermore, a small gap is inevitably formed between the filler and the decorative member. For this purpose, the concrete milk poured on the decorative member unit penetrates into this gap and moves to the surface of the decorative member. In the PC concrete thus obtained, there is a problem that since the surface of the decorative member has a sticking of the concrete, a long cleaning work is required and it takes much time and effort.

As an alternative to a filler such as a rubber base or styrene foam, or a masking tape,
Recently, a method for producing a decorative member implanted PC concrete and a hot melt material for fixing the decorative member used therein have been developed. That is, the decorative member is fitted on the back of the decorative member in a lattice-shaped form formed by vertically and horizontally intersecting plates that match the dimensions of the decorative member having a predetermined size, the gap between the fitted decorative member, and the decorative member. In the upper part, the hot melt material is melted and poured, and after the hot melt material is solidified, the decorative member unit composed of the decorative member embedded in the hot melt material is removed from the mold, and the decorative member is turned upside down. This is a method for producing PC concrete in which concrete is cast on the upper part of a decorative member from steam, and after steam curing, the hot melt material is peeled off.

[0007] Since the hot melt used in this production method is a composition containing an amorphous polyolefin as a main component, it is very hard and lacks flexibility. The problem remains that it is difficult and takes much time. Furthermore, when the recovered hot melt material is melted and reused, as the number of uses increases, the thermal stability is poor, so that thermal decomposition proceeds and cohesive force is lost. As a result, the film may be cut or glue residue may occur during the peeling operation. There is a problem that a long cleaning work is required, and much labor and cost are required.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a decorative material for PC concrete.
It has good adhesion to the decorative member, prevents contamination of the decorative member surface by concrete milk, and has an appropriate melt viscosity, so it maintains excellent workability while maintaining excellent flexibility, thermal stability, and heat resistance. An object of the present invention is to provide a hot melt composition which has releasability and can be reused several times.

[0009]

SUMMARY OF THE INVENTION The present invention is a peelable hot melt composition containing a styrene-based thermoplastic elastomer.

[0010] The peelable hot melt composition of the present invention comprises:
10 to 40% by weight of a styrene-based thermoplastic elastomer,
5 to 60% by weight of tackifying resin and 1 of process oil
Those containing 0 to 70% by weight and 10 to 40% by weight of a wax are preferred.

Here, as the styrene-based thermoplastic elastomer, styrene-butadiene-styrene (SB)
S) and / or an unsaturated rubber type block copolymer selected from styrene-isoprene-styrene (SIS), and styrene-ethylene-butylene-styrene (SEBS) and / or styrene-ethylene-propylene-styrene (SEPS) It is preferable to use at least one selected from the group consisting of saturated rubber type block copolymers selected from the group consisting of:

As tackifying resins, petroleum resins (aliphatic, aromatic, copolymerized and alicyclic), hydrogenated petroleum resins, rosin and its derivatives, ternpene resins and their hydrogens It is preferable to use at least one selected from the group consisting of oxides.

Further, it is preferable to use at least one selected from the group consisting of paraffinic, naphthenic and aromatic oils as the process oil.

Further, as the wax, it is preferable to use at least one selected from the group consisting of polyethylene wax, polypropylene wax, Fischer-Tropsch wax, paraffin wax, and microcrystalline wax.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The styrenic thermoplastic elastomer used in the present invention is a block copolymer having a polystyrene phase (S) at both ends, and polybutadiene (B), polyisoprene (I) and polyolefin in an intermediate phase. There are three basic types with [ethylene / butylene (EB) or ethylene / propylene (EP)], which are called SBS, SIS and SEBS or SEPS, respectively. SEBS is SBS and SEPS is SIS saturated by hydrogenation to eliminate double bonds, and is a new thermoplastic elastomer with improved heat resistance and weather resistance. As specific examples, "Califlex TR" and "Clayton G" (manufactured by Shell Chemical Co., Ltd.), "JSR TR"
(Manufactured by Nippon Synthetic Rubber Co., Ltd.), "Septon" (manufactured by Kuraray Co., Ltd.), and "Quintac" (manufactured by Zeon Corporation).

When the molecular weight of the thermoplastic elastomer is low, the cohesive force of the composition is low, so that the creep resistance is low, and the film is cut off or adhesive residue occurs at the time of peeling. When pouring into the top of
Since the workability deteriorates, the melt index (200
C., 5 Kg) in the range of 0 to 20 g / min. Further, in order to maintain blocking resistance and peelability at room temperature, it is preferable to use a material having a high styrene / rubber ratio and a high modulus. SI
Hot melt compositions based on S or SBS have essentially poor heat resistance due to double bonds remaining in the rubber phase. At the time of reuse, the recovered hot melt material for fixing a decorative member must be melted many times. In order to maintain thermal stability, SEBS and SEPS obtained by hydrogenating them are used. It is desirable. The weight ratio of the styrenic thermoplastic elastomer to the entire hot melt composition can be, for example, about 10 to 40% by weight, but is preferably 15 to 30% by weight. If it is less than 10% by weight, the heat resistance and strength of the hot melt material will be weak, and the blocking resistance at room temperature will be poor. On the other hand, 40
If the content is more than 10% by weight, the melt viscosity is too high, and the workability of pouring decreases. In the composition of the present invention, the styrene-based thermoplastic elastomer may be used alone or in combination of two or more.

The tackifying resin, which is a component of the present invention, is blended to adjust the viscosity of the thermoplastic elastomer at the time of melting and to improve the wettability and adhesion to the decorative member. This tackifying resin is mixed with a thermoplastic elastomer, improves the hot tack of the base polymer at the time of heating, and at room temperature, any material may be used as long as it does not separate from the thermoplastic elastomer. In order to obtain thermal stability and creep resistance, a tackifying resin which is preferably hydrogenated and has a ring and ball softening point of 80 ° C. or more is preferred. If the temperature is lower than 80 ° C, the composition lacks heat resistance, and the hot melt material is deformed during steam curing, and loses the role of fixing the decorative member. The weight ratio of the tackifier resin to the entire hot melt composition can be, for example, about 5 to 60% by weight, but is preferably 20 to 50% by weight. When the content is less than 5% by weight, the adhesion to the decorative member is weakened, so that the decorative member is easily peeled off after solidification. On the other hand, if it exceeds 60% by weight, the adhesion is too strong and the flexibility is lost, so that the peelability deteriorates.

The process oil, which is another component of the present invention, is compounded to adjust the viscosity of the thermoplastic elastomer at the time of melting, to improve the wettability to decorative members, and to reduce the cost. Although any of paraffinic, naphthenic and aromatic oils can be used,
Since aromatic oils dissolve styrene domains and reduce the cohesive strength of the composition, it is desirable to use paraffinic and naphthenic oils for the hot melt composition. The weight ratio of the hot melt composition to the whole can be, for example, about 10 to 70% by weight, but is preferably 30 to 50% by weight. If it is less than 10% by weight, the melt viscosity does not decrease so much, and the workability of pouring becomes poor. On the other hand, if it exceeds 70% by weight, the oil tends to bleed from the hot melt material, and contaminates the surface of the decorative member.

The wax, which is another component of the present invention, is blended to lower the melt viscosity of the composition and to quickly solidify the hot melt material after being poured into the upper part of the decorative member. Any material can be used as long as it has good compatibility with the thermoplastic elastomer, and is not particularly limited.However, if the amount added to the entire hot melt composition increases, the flexibility of the hot melt disappears, and shrinkage also occurs. Since the size becomes large and it becomes difficult to maintain the dimensional stability of the decorative member unit, it is usually 10 to 40% by weight, preferably 15 to 30% by weight. If it is less than 10% by weight, the solidification rate of the hot melt material after pouring becomes slow. On the other hand, if it exceeds 40% by weight, the dimensional stability is deteriorated because the hot melt material solidifies and then contracts more.

The present inventors have found that such a composition has good adhesion to a decorative member and has an appropriate melt viscosity, so that it has excellent flexibility and heat while maintaining good workability. It has been found that it has stability and peelability. The composition of the present invention may contain, as necessary, a stabilizer, an antioxidant, a filler, a pigment, and the like used in a normal hot melt composition, as long as the object of the present invention is not impaired. Can be.

[0021]

The present invention will be described below in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples. The compositions in Examples and Comparative Examples are parts by weight unless otherwise specified. Example 1, Comparative Examples 1-4

Preparation of Hot Melt Material Using the raw material formulations shown in Table 1, these were kneaded with a kneader.
Hot melt materials (A to E) were obtained by kneading at 70 ° C. for 2 hours. The raw material of the hot melt composition is
It is as follows. "Clayton G-1652" (manufactured by Shell Chemical Co., Ltd.) was used as the styrene-based thermoplastic elastomer. As another thermoplastic resin, an ethylene-vinyl acetate copolymer "Ultracene 680"
(Manufactured by Tosoh Corporation) was used. "Vestplasto 750" as an amorphous polyolefin
(Manufactured by Huls Co., Ltd.), "UT 2215" (manufactured by Ube Lexen Co., Ltd.) and "SUNATTACK" (manufactured by Chiba Fine Chemical Co., Ltd.) were used. "Alcon P-100" (manufactured by Arakawa Chemical Co., Ltd.) was used as the alicyclic saturated hydrocarbon resin. As process oil, "N
U-80 "(made by Idemitsu Petrochemical Co., Ltd.) and" PUREX
-30 "(manufactured by Esso Oil Co., Ltd.). As the wax, "VISCOL 660P" (manufactured by Sanyo Chemical Co., Ltd.) and "Paraffin Wax 155" (manufactured by Wax Co., Ltd.) were used. In addition, as an antioxidant, "Irganox 1010" (manufactured by Ciba-Geigy Corporation)
Was used.

Manufacturing Method A split skin tile having an uneven surface as shown in FIG. 1 was used as a mold for a decorative member unit having a size of 900 cm ² as shown in FIG. 2 [partition plate (1 in FIG. 2). It was made of aluminum and had a thickness of 6 mm and a height of 10 mm], and a hot melt material obtained by the raw material formulation shown in Table 1 was melted at 170 ° C. and poured to produce a decorative member unit. After the molten hot-melt material was solidified, it was released from the mold to form one decorative member unit. next,
The decorative member unit was cast with concrete with the surface of the hot melt facing downward, cured, and the hot melt was peeled off to obtain PC concrete.

Practical experiments were performed on the hot-melt materials obtained in Formulations A to E, and the following physical properties were observed. Cohesive strength : strength when the solidified hot melt material is peeled from PC concrete. 〇: Peeled off with one continuous film. Δ: The film may be broken. X: The film was broken and could not be peeled. Fluidity : Ease of flow when flowing a molten hot melt material. 〇: The surface becomes completely flat. Δ: The surface is slightly uneven. X: The surface is not flat at all. Heat resistance : Deformation of hot melt material by steam curing 〇; No deformation at all. Δ: Partially deformed. ×: completely deformed. Peelability : Easiness of peeling when solidified hot melt material is peeled from PC concrete. 〇; easily peels off. Δ: Partially peeled off. Compatibility : compatibility at the time of melting. 〇; completely compatible. Δ: Partially compatible. Stainability : Stain on the surface of the decorative member. 〇; No contamination at all. Δ: Partial contamination. X: Completely contaminated. Table 1 shows the results of these observations.

[0025]

[Table 1]

As is evident from the observation results in Table 1, the hot-melt material prepared in Formulation A can be easily peeled off with a single continuous film, and contamination of the hot-melt material on the decorative member surface and concrete milk No migration was observed.

[0027]

The peelable hot melt composition for fixing decorative members of precast concrete according to the present invention has the following features. The hot melt composition has good adhesion to the decorative member, so that the concrete milk does not flow to the surface of the decorative member, and has a proper flexibility,
When peeling off from a concrete decorative member, it can be easily peeled off. By changing the composition of the hot melt composition,
The thermal stability of the composition can be greatly improved. The number of recycling by re-melting can be increased,
It is economical.

[Brief description of the drawings]

FIG. 1 is a plan view of a split-skin tile having irregularities on its surface.

FIG. 2 is a schematic view showing a part of a side surface in which a cracked tile having irregularities on its surface is fitted into a form of a decorative member unit.

[Explanation of symbols]

 1 Partition plate

Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // B28B 1/16 B28B 1/16 (C08L 53/02 57:02) (C08L 53/02 93:04)

Claims (6)

[Claims] 1. A strippable hot-melt composition comprising a styrene-based thermoplastic elastomer. 2. A styrenic thermoplastic elastomer of 10
-40% by weight, 5-60% by weight of tackifying resin, 10-70% by weight of process oil, and 10% of wax
The releasable hot melt composition according to claim 1, which comprises about 40% by weight. 3. An unsaturated rubber type block copolymer composed of styrene-butadiene-styrene (SBS) and / or styrene-isoprene-styrene (SIS) as a styrene-based thermoplastic elastomer, and styrene-ethylene-butylene- The peelable hot melt composition according to claim 2, wherein at least one selected from a saturated rubber type block copolymer consisting of styrene (SEBS) and / or styrene-ethylene-propylene-styrene (SEPS) is used. 4. As the tackifying resin, petroleum resin (aliphatic, aromatic, copolymerized or alicyclic), hydrogenated petroleum resin, rosin or a derivative thereof, ternpene resin or hydrogen thereof The strippable hot melt composition according to claim 2, wherein at least one selected from the group consisting of oxides is used. 5. A process oil, wherein the process oil is paraffinic.
3. The peelable hot melt composition according to claim 2, wherein at least one selected from the group consisting of naphthenic and aromatic oils is used. 6. The peelable hot melt composition according to claim 2, wherein at least one selected from the group consisting of polyethylene wax, polypropylene wax, Fischer-Tropsch wax, paraffin wax, and microcrystalline wax is used as the wax.