JPS63199217A - Polyurethane resin composition for casting - Google Patents

Abstract

PURPOSE:To obtain the titled composition suitable for producing ornamental badges, etc., having excellent flexing resistance, weather resistance, impact resistance, heat resistance, etc., by blending a polyol compound of specific composition with a diisocyanate component of specific composition in a specific ratio. CONSTITUTION:The aimed composition consisting of (I) 100pts.wt. polyol component containing (A) 50-70wt.% polyester triol and polyester triol having 100-1,000 molecular weight and (B) 30-50wt.% polyether diol having 1,000-3,000 molecular weight and (II) 90-105wt.% diisocyanate component containing (C) 50-100wt.% reaction product obtained by reacting an alicyclic diisocyanate with a polyether having 300-400 molecular weight in a molar ratio of diisocyanate/triol of 2.5-6 and (D) 0-50wt.% trimer of hexamethylene diisocyanate.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a casting polyurethane resin composition that can be advantageously used in the production of decorative insignia. The present invention relates to a polyurethane resin composition for casting that has excellent properties such as hardness, impact resistance, and heat resistance.

[Conventional technology]

Decorative emblems, which have been widely used in many industrial fields, are decorations such as letters, figures, patterns, etc., made by painting, printing, plating, hot stamping, etc., or a combination of these, on any substrate surface that forms the base of the emblem. The decorative insignia obtained is manufactured by applying a liquid plastic composition to the decorative surface, then casting the liquid plastic composition in a heaped manner to form a convex lens due to the surface tension of the liquid plastic, and curing. They are used as badges, name plates, etc., attached to products such as automobiles.

For example, Japanese Patent Publication No. 58-1680 describes a liquid plastic composition containing 40 to 50% of a polyol portion consisting of bifunctional, trifunctional and/or tetrafunctional polypropylene glycol, and 2 to 50% of aliphatic diisocyanate.
A polyurethane composition containing 60 to 50% urethane prepolymer reacted with a tetrafunctional polyol is cast onto the surface of a decorated substrate to form a convex lens, and then cured to form a vitreous enamel. A method of making a decorative insignia is described which forms a hard (80-85 Shore "D" hardness) transparent plastic layer that can be used as an alternative.

[Problem that the invention seeks to solve]

The decorative insignia obtained by the method described in the above publication has the advantage of being resistant to abuse due to detergents and impact, and has excellent water resistance, moisture resistance, and acid resistance. The following problems arise due to the use of resin.

(I) Decorative insignias are hard and have poor flexibility, making it difficult to attach them to curved surfaces.

(2) If it is forcibly attached to a curved surface, bending stress is applied to the resin layer, which causes cracks to occur during long-term use, damaging the appearance of the decorative insignia. Especially when used outdoors under weather conditions, stress cracks occur in a very short period of time, making it unsuitable for outdoor use.

Therefore, the present invention provides the above-mentioned (I) without impairing the advantages of the decorative emblem obtained by the method described in the above-mentioned publication.
The purpose is to solve the problem in (2), and in particular, it is a casting product that has excellent flexibility and bending resistance and does not cause stress cracks even when used on curved surfaces. The purpose is to provide a polyurethane resin composition.

[Means for solving problems]

That is, the present invention provides (a) a polyester triol and a polyether triol having a molecular weight of 100 to 1000 (
Hereinafter, polyol component (I) 1 consisting of 50 to 70% by weight of triol (referred to as a5) and (b) 30 to 50% by weight of polyether diol with a molecular weight of 1000 to 3000
(c) 50 to 100 parts by weight of a reaction product obtained by reacting an alicyclic diisocyanate and a polyether triol having a molecular weight of 300 to 400 at a diisocyanate/triol molar ratio of 2.5 to 6. ,
and (d) a trimer of hexamethylene diisocyanate,
Diisocyanate component (II) consisting of 0 to 50% by weight
90-105! By providing a casting polyurethane resin composition comprising i parts of

In the polyurethane resin composition for casting of the present invention, it is essential to use the polyol component (I) as a mixture of the above-mentioned triol (a) and polyether diol (b). (a)
is a component that imparts preferable abrasion resistance, weather resistance, impact resistance, etc. to the finally obtained cured polyurethane resin product, and those having a molecular weight of 100 to 1000 can be used. Specific examples of triols that can be used include polyester triols obtained by ring-opening addition polymerization of ε-caprolactone using triols such as glycerin, trimethylolpropane, and hexanetriol as starting materials, and glycerin, trimethylolpropane, These include polyethertriols obtained by addition polymerizing alkylene oxide, tetrahydrofuran, etc. using hexanetriol etc. as a starting material.

The polyether diol (b) is a component that imparts preferable flexibility or flexibility to the cured polyurethane resin, and those having a molecular ff of 11,000 to 3,000 are used. The molecular weight of polyether diol (b) is 100
If it is less than 0, the flexibility will be poor especially at low temperatures, and 3
If it is larger than 000, there will be drawbacks such as the inability to obtain a cast product with excellent surface smoothness. Specific examples of the polyether diol (b) that can be used include those obtained by addition polymerizing alkylene oxide and tetrahydrofuran to diols such as ethylene glycol and polypropylene glycol.

The triol (a) and polyether diol (b) in the polyol component (I) are (a)/(b) −
It is used by mixing at a weight percent ratio of 50-70/30-50, but if the mixing ratio is out of this range, performance such as flexibility, abrasion resistance, impact resistance, weather resistance, etc. will deteriorate, especially When the polyether diol (b) is less than 30% by weight, the flexibility, which is a feature of the present invention, is reduced and stress cracks are likely to occur.On the other hand, when it is more than 50% by weight, the flexibility becomes excessive and the resulting product is This is not preferable because the surface of the cast product becomes sticky.

The diisocyanate component (II), which is the other component constituting the casting polyurethane resin composition of the present invention, contains 50 to 100% by weight of the reaction product (c) of an alicyclic diisocyanate and a polyether triol, and 3ffi form (d) of methylene diisocyanate 0-50% by weight
The reaction product (c) is an alicyclic diisocyanate (specific examples include hydrogenated diphenylmethane diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated isophorone diisocyanate, Hydrogenated 1,5-naphthalene diisocyanate, 1-methyl, 4-(isocyanatomethyl)cyclohexyl isocyanate, 1,4-cyclohexane diisocyanate, etc.) and polyether triols with a molecular weight of 300 to 400 (specific examples include polyethylene glycol polypropylene glycol triol, polypropylene glycol triol, polyethylene glycol polypropylene glycol triol, etc.) in an amount such that the diisocyanate/polyether triol molar ratio of the diisocyanate/polyether triol of the alicyclic diisocyanate is in the range of 2.5 to 6. It is a reaction product with an excess of NCO groups.

In addition, hexamethylene diisocyanate trimer (d), which can be used in combination with the above reaction product (c), can be used in combination with the "fluctuation phenomenon" that often occurs on the surface of polyurethane resin castings (due to uneven shrinkage during curing). It is effective in preventing the phenomenon of hardening in the form of ripples, especially in combination with the above reaction product (c).
It is preferable to use it in a range of % by weight. Specific examples of hexamethylene diisocyanate trimers that can be used include Coronate EH (trade name, manufactured by Nippon Polyurethane Co., Ltd.), Parnock D980 and D981 (trade name, manufactured by Dainippon Ink and Chemicals), and Dismodur N-3390 (trade name, manufactured by Dainippon Ink and Chemicals). (product name, manufactured by Sumitomo Bayer Urethane Co., Ltd.), etc.

The polyurethane resin composition for casting of the present invention contains the polyol component (I) having the above-mentioned specific composition and the diisocyanate component (II) having the specific composition, based on 100 parts by weight of component (I) and 90 to 90 parts by weight of component (II). By blending in the range of 105 parts by weight, flexibility with Shore II A 11 hardness of 80 to 95 can be obtained, and a cured polyurethane resin product with excellent flexibility can be formed. If the blending ratio is out of the above range, the blending balance of NGOloH in the composition will be disrupted, and weather resistance, impact resistance, hydrolysis resistance, etc. will be adversely affected.

In addition to the polyol component (I) and diisocyanate component (II), various additives such as a curing accelerator (
(catalysts), ultraviolet absorbers, antioxidants, antifoaming agents, light stabilizers, pigments, dyes, leveling agents, etc., in conventional amounts.

The thus obtained polyurethane resin composition of the present invention is
It is a liquid material suitable for casting, and when this is cast onto an insignia or other arbitrary substrate, a liquid polyurethane resin layer rises up into a convex lens shape on the substrate due to the surface tension of the liquid. It is formed.

Then, the liquid polyurethane is cured by a suitable curing treatment such as heating, and the desired product such as a decorative insignia can be obtained.

The application examples of the casting polyurethane resin composition of the present invention have been described above for decorative insignia, but the present invention is not limited thereto, and includes, for example, accessories such as badges and brooches, buttons, etc. It can be used for a wide range of purposes, such as decorative parts such as dial knobs, and side moldings of automobiles. Furthermore, the material of the substrate may be metal, plastic, glass, paper, wood, or the like.

【Example〕

The present invention will be explained in further detail by the following examples. In addition, the blending ratio of each component in the examples is shown in parts by weight.

Example 1 Polyester triol (manufactured by Daicel Chemical Industries, Ltd., Plaxel 303 (molecule ff1300)/Plaxel 308
(molecular weight 850) -26 parts/14 parts) 40 parts, polypropylene glycol triol (manufactured by Sanyo Chemical Industries, Ltd., Sannix GP-400, molecular ff1400) 20 parts, polypropylene glycol diol (manufactured by Sanyo Chemical Industries, Ltd.,
Sunbren PP-1000, molecular weight 1000) 40 parts,
DBTDL (dibutyltin dilaurate-curing catalyst) 0
．． 1 part of polyol component (a), 1 part of polypropylene glycol triol (manufactured by Asahi Denka Kogyo Co., Ltd., ADEKA Polyether G-300, molecular weight 300), and 4.3 parts of hydrogenated tolylene diisocyanate were reacted. The diisocyanate component (a) was prepared in this manner.

Add each component obtained above to 5 to 20 a+a+Hg
After defoaming for 30 minutes under vacuum, polyol component (a) 1
00 parts and 95.4 parts of diisocyanate component (a) were mixed without forming bubbles, and the mixed liquid was spread to a thickness of 0.5 m.
The resin layer was cast on an aluminum plate having a thickness of about 2 m and was subjected to an effect treatment at 80° C. for 30 minutes.

When the obtained cast product was tested according to the test methods (I) to (3) below, it exhibited a smooth and non-adhesive appearance, and there were no defects such as cracks in flexibility. It showed excellent properties.

Test method (I) Appearance: Visually observe whether the appearance of the cast product is normal.

(2) Non-adhesiveness: Performed according to the non-adhesive test method specified in JIS K5400 6.8. However, the traces of the cloth grain are observed after being left for 24 hours.

(3) Flexibility: Wrap it around the outside of a 40 mm diameter cylinder with the substrate inside and the resin layer outside, and in this state observe the resin layer for defects such as cracks and cracks. In addition, a 300-hour sunshine weather meter test is conducted in this state, and the presence or absence of defects is similarly observed.

Comparative Example 1 Polypropylene glycol triol (manufactured by BASF Wyandotte, TP-440, molecule m
425) 77.6 parts, polypropylene glycol diol (manufactured by BASF Wyandotte, P-410, molecular weight 425) 19.4 parts, DBTDL 1.1 parts, and polypropylene glycol TP-44015. Part, Hiren W (E, 1. Manufactured by DuPont ψ de Nemours, aliphatic diisocyanate) 85
The diisocyanate component (a') was adjusted according to the composition of 1 part.

44.5 parts of the polyol component (a'') and 55.5 parts of the diisocyanate component (a') were mixed in the same manner as in Example 1, and then a cast product was prepared.The obtained cast product was tested in the same manner as above. As a result, the appearance and non-adhesion properties were good, but the cast product was extremely hard and had numerous cracks in its flexibility, making it unsuitable for adhesive use on curved surfaces. .

Examples 2 to 5 and Comparative Examples 2 to 6 Polyol components (b) to Cf) were prepared according to the formulations shown in Table 1 below.
In addition, diisocyanate components (b) to (f
) were adjusted respectively. In addition, in the polyol components in Table 1, (c) and (d) use polyether diols whose molecular weights are outside the range of the present invention, and (
In cases e) and (f), the mixing ratio of polyester/polyether triol and polyether diol is outside the range of the present invention. Furthermore, in the diisocyanate component in Table 2, (f) contains a large amount of hexamethylene diisocyanate trimer which is out of the range of the present invention.

Table 1 (Ne) Sannics CP-Tooo: Sanyo Chemical Industries, Ltd., polypropylene glycol triol, molecular weight 1
000 (Kyoto) Sunburen: Sanyo I℃ Rokentsuji, polypropylene glycol diol, PP-750 (molecular weight 750
), PP-3000 (molecular weight 3000), PP-40
00 (molecular weight 4000) Table 2 (Zero) Adeka Polyether G-400: Manufactured by Layered Chemical Industry Co., Ltd., polypropylene glycol triol, molecular weight 4
00 The polyol components (b) to (f) obtained above and the diisocyanate components (b) to (f) were mixed and cast molded in the same manner as in Example 1 at the compounding ratio shown in Table 3 below, and then tested. The nine test results are shown in Table 3.

As is clear from the results in Table 3 above, the cast products shown in Examples 2 to 5, which correspond to the implementation of the present invention, exhibited good characteristics in terms of appearance, viscosity, and flexibility. Ta. On the other hand, the cast products shown in Comparative Examples 2 to 6, which do not fall under the practice of the present invention, do not have performance that satisfies all the characteristics of appearance, non-adhesiveness, and bending resistance. , it was inappropriate in terms of practicality.

〔Effect of the invention〕

According to the polyurethane resin composition for casting according to the present invention,
Since it can form a cured product with excellent flexibility, it can be bent and attached to objects with curved surfaces, whereas conventional products could only be used on flat surfaces. It has an extremely superior effect in that it can be used in a much wider range of applications compared to the conventional method.

Claims (1)

Scope of Claims: A polyol component (I ) 100 parts by weight, (
c) 50 to 100% by weight of a reaction product obtained by reacting an alicyclic diisocyanate and a polyether triol having a molecular weight of 300 to 400 in a diisocyanate/triol molar ratio of 2.5 to 6, and (d ) Hexamethylene diisocyanate trimer 0-5
90 to 105 parts by weight of diisocyanate component (II) containing 0% by weight.