JP2002088213A - Water-soluble resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water-soluble resin composition which is useful as an organic binder, i.e., an indispensable component for a paint, an adhesive, and a coating agent, is environmentally friendly, and is excellent in adhesiveness and water resistance. SOLUTION: This resin composition is prepared by compounding polyvinyl alcohol with a terpene-maleic anhydride copolymer resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a binder and a vehicle component essential for the construction of paints, inks, various coating agents, surface protective films, etc., and more particularly to an aqueous resin composition relating to safety and health and the environment. It is.

[0002]

2. Description of the Related Art Various resins such as acrylic resins, urethane resins, epoxy resins, and polyester resins are used as binders (generally, resin compositions) used for paints, inks, adhesives, various coating agents, surface protective films, and the like. Is used. In recent years, a water-soluble resin composition has attracted attention as a binder for these from the environmental point of view. As the water-soluble binder or vehicle component, polyvinyl alcohol (hereinafter referred to as PVA) -based resin is often used from the viewpoint of cost. However, PVA-based resins generally have low water resistance even after heat treatment and cannot be used in an environment of high humidity or where rainwater is involved. As a means of improving the water resistance of a PVA-based resin composition, it is known that a crosslinking reaction is caused by a urea-melamine-based crosslinking agent or a saturated dicarboxylic acid-based crosslinking agent. The working environment deteriorates due to the generation of formalin gas, which is not preferable. In the case of a saturated dicarboxylic acid, discoloration or hardening of the resin due to curing tends to cause a decrease in the adhesion of the coating film, peeling of the binder, and cracking.

[0003]

DISCLOSURE OF THE INVENTION The present invention provides a water-soluble resin composition which improves the conventional disadvantages of a PVA-based resin composition, such as water resistance and adhesion, and has a good working environment. It is intended to provide a bonding material used for a surface protective film or the like.

[0004]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have completed the present invention. That is, the present invention is a water-soluble resin composition comprising a terpene-maleic anhydride copolymer resin, which is a copolymer of terpene and maleic anhydride, mixed with PVA.

The terpene / maleic anhydride copolymer used in the present invention is produced by radical polymerization of a terpene compound and maleic anhydride. The radical polymerization of a terpene compound and maleic anhydride is described in Eur. Po
lym. J. , 17, 961-968, 1981 and Eu.
r. Polym. J. , 24 (5), 453-456,
1988, Macromol. Chem. Phys. ,
195, 1848 to 1850, 1994 describe a production method and the like. Further, Japanese Patent Application Laid-Open No. 9-511012 discloses a solventless production method. That is, it is manufactured by the following method. A terpene compound and a solvent such as maleic anhydride, tetrahydrofuran or toluene are charged into a flask as a raw material monomer, and an organic peroxide such as BPO is dropped as a reaction initiator and reacted for several hours to be synthesized. The obtained copolymer has a yield of 95% or more, and the properties are molecular weight (Mw) = 1000 to 50,000 depending on the reaction conditions.

As the starting terpene compound, α-pinene,
β-pinene, limonene, dipentene, terpinolene,
Examples include pinene, terpinene, mentadiene, terpene alcohol, terpene aldehyde, and the like, and α-pinene, β-pinene, limonene, and dipentene are particularly preferable.

The copolymerization ratio of the terpene compound and maleic anhydride of the terpene-maleic anhydride copolymer resin used in the present invention is not particularly limited, but from the viewpoint of water resistance and adhesion, the terpene compound / maleic anhydride is used. Acid = 1 /
0.25 to 1 / 2.5 mole is suitably used. When the copolymerization ratio of maleic anhydride is less than 1 / 0.25 mol of terpene compound / maleic anhydride, the water resistance of the coating film is insufficient, and the copolymerization ratio of maleic anhydride is terpene compound / maleic anhydride = If it is larger than 1 / 2.5 mol, the adhesive strength will be deteriorated. In addition, imide compounds that are derivatives of the terpene-maleic anhydride copolymer resin, esterified compounds, metal salts, ammonium salts, and the like are also suitably used, and in the following description, the copolymer resin includes those derivatives. I do.

The proportion of the terpene-maleic anhydride copolymer resin blended in the PVA is not particularly limited, but is 1.0 to 80% by weight. However, the total of PVA and terpene-maleic anhydride copolymer resin is 100% by weight.
It is. Furthermore, the compounding ratio of the terpene-maleic anhydride copolymer resin is particularly preferably 5 to 50% by weight.
If it is less than 1.0%, the compounding effect is poor, and if it exceeds 80%, the adhesive strength is reduced. Although the molecular weight and the degree of saponification of PVA used in the present invention are not particularly limited, the degree of polymerization is 500 to 35.
Those having a saponification degree of 20 to 90 mol% are preferably used.

The water-soluble resin composition of the present invention can be obtained by mixing an aqueous solution of a terpene-maleic anhydride copolymer resin and an aqueous PVA solution. Each of the paint, ink, adhesive, various coating agents, surface protective film, etc. In the above application, various materials for imparting functions, such as pigments, dyes, magnetic materials, fillers, stabilizers, and antioxidants, can be appropriately compounded. The water-soluble resin composition may be used in various forms such as coating, film formation, impregnation, and dispersion.

The water-soluble resin composition of the present invention can provide a PVA-based resin composition having high water resistance and high adhesive strength by blending a terpene-maleic anhydride copolymer resin with PVA. The present inventors consider the reason as follows. By mixing a copolymer of terpene and maleic anhydride into PVA, the carboxyl residue of the terpene-maleic anhydride copolymer reacts with the hydroxyl group of PVA in a drying and heat treatment step to form a three-dimensional cross-link, thereby improving water resistance and adhesiveness. Has improved. INDUSTRIAL APPLICABILITY The PVA-based resin composition of the present invention improves water resistance and adhesiveness, which are conventional drawbacks, and provides a water-soluble resin composition having a favorable working environment. Various coating agents such as undercoating agent, insulation coating agent, magnetic coating agent, coloring coating agent, as well as film, impregnating agent, dispersant, paper, office equipment, civil engineering construction, house, electric and electronic, machinery, automobile, aircraft, etc. It can be used advantageously in a wide range of fields.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The water-soluble resin composition of the present invention will be described below with reference to synthesis examples of the present invention, examples as adhesive coating films, and comparative examples, but the present invention does not exceed the gist thereof. It is not limited to these uses and usage forms as long as they are used. Synthesis Example 1 68 g of limonene, 98 g of maleic anhydride, and 166 g of tetrahydrofuran were charged into a flask equipped with a stirrer, a condenser, and a thermometer, and heated to 60 ° C. under a nitrogen stream. After the internal temperature is stabilized, BPO is added dropwise as an initiator over 1 hour. After completion of the dropwise addition, a post-reaction was carried out, and the copolymer was recovered by filtration, washed with hexane and dried to obtain a resin. The yield of the obtained copolymer was 97%, and the average molecular weight (Mw) in terms of polystyrene was 150 by GPC (gel permeation chromatography).
00, acid value = 465.

Example 1 5% by weight of polyvinyl alcohol (Kuraray Co., Ltd .: PVA420) having a degree of polymerization of 2,000 and a degree of saponification of 80 mol%
Aqueous solution (Preparation solution A) and 5% by weight aqueous alkali solution of terpene-maleic anhydride copolymer resin of Synthesis example 1 (Preparation solution B)
Was prepared. The neutralization degree of the terpene-maleic anhydride copolymer aqueous alkali solution was adjusted to 50% with potassium hydroxide. The preparations A and B were mixed at a ratio of 70:30 to prepare a PVA aqueous solution containing 30% by weight of a terpene-maleic anhydride copolymer resin. Next, it was applied to a 25 μm polyester film (corona treated product) using a bar coater. Thereafter, drying at 80 ° C. × 5 minutes (in a dryer) and heat treatment at 180 ° C. × 5 minutes were performed to form a coating film of the resin composition on the film. At this time, the thickness of the coating film was 5 μm. (1) Measurement of Adhesive Strength A paper tape coated with a starch-based aqueous paste on one side and the above-mentioned coating film were sampled in a width of 25 mm, and the paste surfaces were attached to each other. The lamination was performed by adding water to the starch paste and laminating at 60 ° C. for 5 minutes, and left at room temperature for 24 hours. Thereafter, the 180 ° peel adhesion was measured with a tensile tester. (2) Evaluation of Water Resistance The coating film was immersed in hot water of 100 ° C. for 30 minutes, and the adhesion was measured by the method of the above (1). Table 1 shows the evaluation results.

Examples 2 to 5 Evaluation was performed in exactly the same manner as in Example 1 except that the mixing ratio of the terpene-maleic anhydride copolymer resin used in Example 1 was changed to 1, 15, 50, and 80% by weight, respectively. did. Table 1 shows the evaluation results.

Comparative Examples 1 to 3 Evaluation was performed in exactly the same manner as in Example 1 except that the mixing ratio of the terpene-maleic anhydride copolymer resin used in Example 1 was changed to 0, 0.5, and 85% by weight, respectively. did. Table 1 shows the evaluation results.

[0015]

[Table 1]

[0016]

According to the present invention, the water-soluble resin composition of the present invention can
Paints, inks, adhesives and surface protective films, overcoating agents to improve the water resistance and adhesiveness, which are disadvantages of the A-based resin composition, and to provide a water-soluble resin composition having a favorable working environment.
Various coating agents such as undercoating agent, insulation coating agent, magnetic coating agent, coloring coating agent, etc., as film, impregnating agent, dispersing agent, paper, office equipment, civil engineering construction, house, electric and electronic, machinery, automobile, aircraft, etc. It can be used advantageously in the field.

Claims (3)

[Claims] 1. A water-soluble resin composition comprising a polyvinyl alcohol and a terpene-maleic anhydride copolymer resin. 2. Polyvinyl alcohol 99 to 20% by weight
The terpene-maleic anhydride copolymer resin has a mixing ratio of 1 to 80% by weight (provided that the total of polyvinyl alcohol and the terpene-maleic anhydride copolymer resin is 100% by weight).
The water-soluble resin composition according to claim 1, wherein 3. A terpene compound, which is a raw material of a terpene-maleic anhydride copolymer resin, comprises α-pinene, β-pinene,
3. The water-soluble resin composition according to claim 1, wherein a terpene-maleic anhydride copolymer which is at least one of dipentene and limonene is used.