JP2000160133A - Two pack type sealing material composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a two pack type sealing material composition that includes a specific organic solvent instead of a plasticizer for imparting flexibility thereto in order, solves problems caused by formulation of plasticizer and is useful for application of sealing materials to civil engineering and construction. SOLUTION: In the two pack type sealing material including a urethane prepolymer bearing chain terminal isocyanate groups as the main component, polyol, filler, plasticizer, and the curing agent components including the curing accelerating catalyst, 2-20 wt.% of a mixture of one or more selected from the group consisting of paraffinic hydrocarbons, polybutenes and naphthenic hydrocarbons, based on the mixture of the main components and the curing agent components are used instead of the plasticizer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention relates to a two-part sealant composition, and more particularly, to a method in which a specific organic solvent is used in place of a plasticizer mainly used to impart flexibility to the sealant. Accordingly, the present invention relates to a two-pack type sealing material composition which is useful for applying a sealing material for civil engineering and construction, particularly for the purpose of solving the problems caused by the blending of a plasticizer.

[0002]

2. Description of the Related Art As a sealing material for civil engineering and construction, a material using a urethane prepolymer containing an isocyanate group at a terminal (hereinafter referred to as a terminal NCO-containing prepolymer) (one liquid) Mold or two-pack type) is often used, and a plasticizer is generally added to impart flexibility to the sealing material. Incidentally, as such a plasticizer, one having excellent compatibility mainly with a prepolymer containing terminal NCO, for example, dioctyl phthalate (D
OP) and aromatic carboxylic esters mainly containing phthalic esters such as diisononyl phthalate; or aliphatic carboxylic esters such as dioctyl adipate (DOA) and dibutyl sebacate; and chlorinated paraffin. However, paint is often applied to the surface after casting the sealing material, in which case the compatible plasticizer migrates to the paint side, softening the paint film or causing paint contamination due to dust adhesion and the like. As a result, there is a problem that the appearance of the coating film is impaired. In particular, due to the recent regulation of volatile organic compounds (VOC), the appearance of the coating film has been further impaired as the water-based paint has been promoted.

On the other hand, a plasticizer that is incompatible with the prepolymer containing terminal NCO has a strong tendency to elute (bleed) from the surface of the sealing material or the bonding interface after the application of the sealing material, thereby impairing the flexibility of the sealing material. At the same time, such incompatibility plasticizers are not used because problems such as impairing the adhesiveness and decreasing the adhesiveness of the paint when the paint is applied occur.

[0004] In order to improve the transferability to the paint by the compatible plasticizer, it has been proposed to use a polyester plasticizer obtained by, for example, reacting an ether with a dibasic acid and a terminal stopper. Japanese Patent Publication No. Hei 6-23379). However, since this polyester plasticizer has a higher viscosity itself than conventional phthalate esters, the workability after compounding is not sufficient, the cost is high, and the surface tack is poor.

[0005]

Means for Solving the Problems Accordingly, the present inventors have:
In order to solve the problems caused by the blending of the plasticizer, studies have been made in the direction of so-called non-plasticization, which eliminates the use of a plasticizer. I) The one-pack type sealing material is a prepolymer containing terminal NCO as a main component. It contains a filler, plasticizer and, if necessary, a curing accelerating catalyst, and forms a cured product by moisture curing.However, if this one-part type is deplasticized, a foaming phenomenon due to carbon dioxide gas occurs. Easy to control foaming. ii) In addition, the one-pack type non-plasticizing has a low curing speed, and particularly has a problem with the curing speed at low temperatures. iii) Further, since the one-pack type is moisture-cured, the number of added parts of the terminal NCO-containing prepolymer can be added only in a smaller amount than that of the two-pack type, and when plasticized, the increase in modulus becomes remarkable. iv) On the other hand, the two-pack type sealing material is composed of a main component composed of a prepolymer containing NCO at the end and a curing component containing a polyol, a filler, a plasticizer and a curing accelerator, and the curing method is urethane. Due to the bond or urea bond, even if the two-pack type is non-plasticized, the problems caused by the one-pack type non-plasticization described in (i) to (iii) can be substantially avoided. v) Therefore, as a result of intensive research focusing on two-pack type non-plasticization, if a specific organic solvent is used for the prepolymer containing NCO at the end, good workability due to low viscosity is ensured, and non-phase In the case of a soluble plasticizer, there was almost no bleeding phenomenon, and it was found that the intended purpose of deplasticization was achieved without impairing the flexibility imparting which was the original role of the plasticizer, and to complete the present invention. Reached.

That is, the present invention relates to a two-pack type sealing material composition comprising a main component comprising a prepolymer containing NCO at a terminal and a curing agent component comprising a polyol, a filler, a plasticizer and a curing accelerator. Instead of
2 to 20% based on the mixture of the main component and the hardener component
(Weight%, the same applies hereinafter), provided is a two-pack type sealing material composition characterized by using one or a mixture of two or more selected from the group consisting of paraffinic hydrocarbons, polybutenes and naphthenic hydrocarbons. Is what you do.

The prepolymer containing a terminal NCO in the present invention is produced by reacting a so-called polyol component with an excess of a polyisocyanate component.
Those having a content of 0.5 to 5% are used.

Examples of the polyol component include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, 4,4'-dihydroxydiphenylmethane, glycerin, 1,2,2 At least one of the compounds having at least two active hydrogen groups in a molecule such as 6-hexanetriol, 1,1,1-trimethylolpropane, pentaerythritol, sorbitol, sucrose, etc. is treated with an alkylene oxide (eg, ethylene oxide, Polyether polyols obtained by addition polymerization of propylene oxide, butylene oxide), other polytetramethylene ether polyols, polymer polyols, polybutadiene polyols, and the like.

[0009] If necessary, ethylene glycol, propylene glycol,
Diethylene glycol, dipropylene glycol, neopentyl glycol, triethylene glycol, tripropylene glycol, 1,3-butanediol, 1,4
-Butanediol, bishydroxyethylhydroquinone, glycerin, 1,2,6-hexanetriol,
Polyhydric alcohols such as 1,1,1-trimethylolpropane, pentaerythritol and diglycerin may be added.

The polyisocyanate component is, for example, 2,4-tolylene diisocyanate or 2,4-tolylene diisocyanate.
6-tolylene diisocyanate or a mixture thereof,
Crude toluylene diisocyanate, 4,4'-diphenylmethane diisocyanate or 2,4'-diphenylmethane diisocyanate or a mixture thereof, crude diphenylmethane diisocyanate, carbozide-modified diphenylmethane diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, dicyclohexyl methane diisocyanate, isophorone diisocyanate, hexa Hydroxylylene diisocyanate and the like.

As the polyol in the present invention, those exemplified for the polyol component as a raw material of the above-mentioned terminal NCO-containing prepolymer may be used. In particular, a polyether polyol is preferable, and in addition, a polyester polyol may be used. And polyetheramine, polyetherpolyamide and the like can also be used. The amount to be used may be usually selected in the range of 200 to 500 parts with respect to 100 parts (parts by weight, hereinafter the same) of the prepolymer containing terminal NCO.

The filler in the present invention includes, for example, calcium carbonate, perlite, clay, talc, barium sulfate, carbon black, vinyl chloride resin, glass,
Silica and the like. The amount used is usually 10
What is necessary is just to select from 100 to 300 parts with respect to 0 parts.

The organic solvent used in place of the plasticizer in the present invention is compatible with the terminal NCO-containing prepolymer and can contribute to the adjustment of viscosity (particularly the reduction of viscosity) of the sealing material composition. Hydrocarbon (including not only straight chain but also isoparaffin having a side chain) (preferably having 8 or more carbon atoms, from liquid to waxy), polybutene (for example, from viscous liquid having an average molecular weight of 300 to 2,000 to viscous liquid) Waxes) and naphthenic hydrocarbons (preferably from liquids having 8 to 20 carbon atoms to waxes), and one or two selected from these groups.
A mixture of more than one kind is used (note that a waxy or solid mixture is used in combination with a liquid one in a dissolved state). The amount of the organic solvent used is important, and is selected in the range of 2 to 20%, preferably 2 to 10%, based on the mixture of the main component and the curing agent component. If it is less than 2%, the effect of lowering the viscosity is not good, and the workability is lowered. If it exceeds 20%, the effect of lowering the viscosity becomes too large,
Problems remain in working characteristics such as dripping and slipping.

The curing accelerating catalyst in the present invention includes, for example, dibutyltin dilaurate, tin octoate,
Heavy metal organic compounds such as lead octoate; tertiary amines such as N-alkylmorpholine and N-alkylpiperazine; The amount to be used may usually be selected in the range of 0.1 to 5% based on the mixture of the main component and the curing agent component.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The two-part sealing material composition according to the present invention comprises a curing composition containing the above-mentioned terminal NCO-containing prepolymer as a main component and the above-mentioned predetermined proportions of a polyol, a filler, an organic solvent and a curing accelerator. It is composed of two liquids and a main component (a part of the organic solvent contained in the curing agent component may be mixed with the main component). In actual use, preferred examples of the mixing ratio (%) of each component in the sealing material after the two-component mixing are shown below. Preferable Example % Main component: Prepolymer containing NCO terminal 15 to 35 Curing component: Polyol 20 to 40 Filler 40 to 60 Organic solvent 2 to 20 Curing accelerating catalyst 0.1 to 3 Accordingly, appropriate amounts of ordinary antioxidants, coloring agents (titanium oxide, organic / inorganic pigments, etc.), thixotropic agents (fine powdered silica, etc.) and the like may be added.

[0016]

Next, the present invention will be described more specifically with reference to examples and comparative examples. Examples 1-4 and Comparative Examples 1-4 Each component having the number of parts shown in Table 1 below, that is, a terminal NCO-containing prepolymer (NCO content 2.95%, viscosity 980)
0 cps / 23 ° C.) [Takenate L-1032, manufactured by Takeda Pharmaceutical Co., Ltd.], and polyol (polypropylene glycol having an OH value of 56) [Takelac 79-56, manufactured by Takeda Pharmaceutical Co., Ltd.], filler (surface treatment) Calcium carbonate)
[Homocal DM, manufactured by Shiraishi Industry Co., Ltd.], organic solvent (isoparaffinic hydrocarbon having 20 carbon atoms, average molecular weight 100)
0 polybutene, naphthenic hydrocarbon having 20 carbon atoms) or plasticizer (DOP, DOA, polyester plasticizer)
And curing accelerator catalyst (lead octoate, lead content 17
%), And these are defoamed and stirred with a planetary mixer for 10 minutes to obtain a sealing material composition.
This sealing material composition was poured into a mold, cured at 20 ° C. for 3 days and at 50 ° C. for 3 days, and was 10 cm long.
A cured sheet having a width of 5 cm and a thickness of 10 mm is prepared.

Performance test a) The hardness of the cured sheet is measured with a Shore A hardness tester (evaluation of flexibility). b) The bleeding property (surface tackiness and dissolution property) of the cured sheet is evaluated by finger touch. c) After the evaluation of the finger touch, an aqueous acrylic emulsion paint was applied to the surface of the cured sheet, and then left to dry at 20 ° C. for 7 days to form a coating film, and then subjected to a heat treatment at 60 ° C. × 14 days. After performing, the softening state of the coating film (softening of the coating film) and the adhesion state by volcanic ash (paint contamination) are evaluated. These evaluations were performed based on the following criteria, and the results are shown in Table 1. Generally, a hardness of 5 to 20 passes in the application of a flexible sealing material.
In less than 5 becomes a mastic-like lacks properties as a rubber, also exceeds 20, it becomes too hard as a sealing material, bleeding problems such members destruction phenomenon ○: No adhesive, △: slightly sticky, × : Softening of a large amount of eluted coating film ○: Not softened, △: Slightly softened, × Softened paint stain ○: No adhesion of volcanic ash observed △: Adhesion of volcanic ash around 50% ×: Almost all adhesion of volcanic ash

[0018]

[Table 1]

[0019]

According to the results shown in Table 1, the first embodiment according to the present invention is shown.
Nos. 4 to 4 show no loss in flexibility due to the omission of the plasticizer, very little or no bleeding phenomenon due to the conventional incompatible plasticizer, excellent surface tackiness, and extremely low paint transferability. In order not to soften the membrane,
It is recognized that no stain is formed on the coating film surface. Although the present invention is applied to a sealing material, it goes without saying that the present invention can be applied to an adhesive, a paint, a waterproof coating material, and a polyurethane molding material.

Continued on the front page F-term (reference) 4H017 AA04 AA25 AA31 AB06 AB07 AB13 AD06 AE03 4J002 BB173 BD03X CK02W CK04W DA036 DE236 DG036 DJ016 DJ036 DJ046 DL006 EA017 EA027 EU138 EU238 EZ008 EZ048 FD01G FD016 G02FD

Claims (1)

[Claims] 1. A two-pack type sealing material composition comprising a main component comprising a urethane prepolymer having an isocyanate group at a terminal and a curing component comprising a polyol, a filler, a plasticizer and a curing acceleration catalyst. Instead of the agent, 2
A two-part sealing material composition, comprising at most 20% by weight of one or a mixture of two or more selected from the group consisting of paraffinic hydrocarbons, polybutenes and naphthenic hydrocarbons.