JPH0711107A - Resin composition for forming surface layer of calender roll - Google Patents

Abstract

PURPOSE:To obtain a resin composition giving on a calender roll a surface layer having advantages that calendering conducted between the coated calender roll and a metal roll imparts excellent surface smoothness to the work, e.g. paper or a magnetic tape, because the surface layer is excellent in heat resistance and impart strength and has a low hardness, and that it has excellent durability because of its reduced compression set. CONSTITUTION:This resin composition comprises a liquid epoxy resin, an aromatic amine hardener, and a product of the reaction of an aromatic diamine with a urethane prepolymer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface layer forming resin composition for calender rolls. More specifically, since it is used as a surface layer forming resin of a calender roll, and when it is run in contact with a metal roll, the calendered object such as paper and magnetic tape has excellent smoothness and a small compression set. A surface layer-forming resin composition capable of obtaining a calendar roll having excellent durability.

[0002]

2. Description of the Related Art Conventionally, cotton rolls, paper rolls, wool rolls and the like have been used as surface layer forming compositions for calender rolls. In recent years, in order to improve these drawbacks, a calendar roll having a surface layer formed of a resin such as polyisocyanurate resin, urethane resin, or epoxy resin (Japanese Patent Publication No. 3-50038) or thermosetting which is liquid at the time of molding There is known a calender roll in which a liquid thermosetting elastomer that is incompatible with the thermosetting resin is micro-dispersed in a thermosetting resin (Japanese Patent Laid-Open No. 1-2823).
No. 98).

[0003]

However, when the hardness of the resin-cured product is lowered in order to obtain the surface smoothness of the calendered object in the rolls formed by these materials, the compression set becomes large and the durability of the roll becomes long. Inferior in properties, heat resistance or impact resistance is impaired, and conversely, if the hardness is increased to reduce the compression set, the surface smoothness of the calendered object deteriorates.

[0004]

Means for Solving the Problems The present inventors have solved the above problems, that is, improved the surface smoothness of an object to be calendered,
As a result of intensive studies for reducing the compression set, they have found that the problem can be solved by mixing a solid urethane oligomer in the epoxy resin composition, and reached the present invention. That is, the present invention relates to a liquid epoxy resin (A), an aromatic amine-based curing agent (B), and an aromatic diamine (C1).
And a reaction product (C) of a urethane prepolymer (C2), which is a surface layer forming resin composition for a calendar roll.

Examples of the liquid epoxy resin (A) used in the present invention include bisphenol A type liquid epoxy resins, bisphenol F type liquid epoxy resins, bisphenol AD type liquid epoxy resins and other bisphenol type liquid epoxy resins, diglycidyl phthalate and the like. Glycidyl ester type liquid epoxy resin, glycidyl amine type liquid epoxy resin such as triglycidyl paraaminophenol, tetraglycidyl diaminodiphenylmethane, tetraglycidyl metaxylylene aniline, diglycidyl aniline, diglycidyl-o-toluidine, 1,6 hexamethylene glycol diglycidyl Ether, neopentyl glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether , Glycerol polyglycidyl ether, polyglycidyl ether type liquid epoxy resin, and mixtures thereof, such as trimethylolpropane polyglycidyl ether, and the like. Among these, preferred are bisphenol A type liquid epoxy resin, bisphenol AD type liquid epoxy resin, bisphenol F
Type liquid epoxy resins and mixtures of these with glycidyl amine type liquid epoxy resins.

The amount of (A) in the composition of the present invention is usually 50.
~ 80% by weight.

The aromatic amine type curing agent (B) used in the present invention includes aromatic primary amine type curing agents such as diaminodiphenylmethane, metaphenylenediamine, diaminodiethylphenylmethane, diaminodimethylphenylmethane and diaminodiphenylsulfone. , Aniline, and their formalin condensates, and the like. As aromatic secondary amine curing agents, epoxy compounds such as butyl glycidyl ether and phenyl glycidyl ether of aromatic primary amines, alkylene oxides,
Examples include modified products of acrylonitrile and the like, N-alkylanilines, and formalin condensates thereof, and the like.
These can be used alone or in combination of two or more. Among these, preferred are aromatic secondary amine type curing agents, and particularly preferred are those containing a formalin condensate of N-methylaniline. The number average molecular weight of the formalin condensate of N-methylaniline is usually 226-
850.

The content of (B) in the composition of the present invention is usually 15 to 60% by weight.

The urethane prepolymer (C2) is (C1)
It is an oligomer having a functional group capable of reacting with, and examples thereof include a polypropylene glycol-based urethane prepolymer and a polyoxytetramethylene glycol-based urethane prepolymer. Among these, preferred are polyoxytetramethylene glycol urethane prepolymers having a number average molecular weight of 3,000 to 30,000, and more preferably a number average molecular weight of 5,000 to 10,000.
Is a polyoxytetramethylene glycol urethane prepolymer.

The urethane prepolymer has a molecular weight of 3,000
If it is less than 0, the effect of reducing compression set is not sufficient, and 3
If it exceeds 10,000, phase separation will occur in the epoxy resin, and it will be difficult to obtain a homogeneous cured product.

In the present invention, examples of (C1) forming the reaction product (C) include those listed as the aromatic amine-based curing agent (B).

The amount of (C) in the composition of the present invention is usually 1 to
It is 15% by weight, preferably 2 to 9% by weight, more preferably 3 to 7% by weight.

When the amount of (C) is 1% by weight or less, the effect of reducing the hardness of the cured product is insufficient, and when it is 15% by weight or more, the compression set becomes large.

If desired, a filler or the like may be added to the composition of the present invention. Specific examples of the iron powder, iron oxide powder, aluminum powder, copper powder, stainless powder, silica powder,
Talc, calcium carbonate, titanium oxide and the like can be mentioned.

The amount in these compositions is usually 0 to 70% by weight.

Various other additives may be added to the composition of the present invention, for example, a defoaming agent, an anti-settling agent, and a curing accelerator.

The amount in these compositions is usually 0 to 3% by weight.
Is.

The composition of the present invention is usually composed of two liquids, a main agent containing (A) and a curing agent containing (B) and (C), but other fillers and the above additives are the main agents. It may be added to either the component or the curing agent component.

By forming a layer obtained by curing the composition of the present invention on the surface of an iron core or the like, it is excellent in heat resistance and has low hardness. An object to be calendered such as a tape is excellent in smoothness, and since the compression set is small, a calendar roll excellent in durability can be prepared. As a method for forming a layer obtained by curing the composition of the present invention on the surface of an iron core or the like, there are a direct casting method and a centrifugal casting method.

Representative examples of making calender rolls using the composition of the present invention are described below. In the direct casting method, after the surface is blasted, an iron core coated with an adhesive or treated with an adhesive layer impregnated with glass cloth, carbon fiber or the like is set in a resin casting mold, and usually 20
After injecting the resin composition of the present invention whose temperature is adjusted to -80 ° C and curing by heating to complete the curing to obtain a surface layer, surface polishing is performed to obtain a calendar roll. In the centrifugal molding method, after curing the above surface layer in a centrifugal molding machine, the obtained cylindrical surface layer is adhered to the iron core treated as described above and surface polishing is performed to obtain a calendar roll.

The method of mixing the composition of the present invention includes:
(A), (B), (C) may be mixed at the same time,
Further, since (C) is a solid, (C) may be dissolved in (B) in advance, and this may be mixed with (A). Ordinarily, (B) and (C1) are the same. Then, (B)
Is used in a large excess relative to (C2), a mixture of (B) and (C) is prepared in one step by reacting a predetermined amount of (C2) in (B). You can mix.

[0022]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. In addition, the part in an Example represents a weight part.

Production Example 1 Tetraglycidyldiaminodiphenylmethane [trade name Sumiepoxy ELM-434, manufactured by Sumitomo Chemical Co., Ltd.] 419
581 parts of a bisphenol AD type epoxy resin [trade name Epomic R-710, manufactured by Mitsui Petrochemical Co., Ltd.] was uniformly dissolved in a part to obtain a viscous liquid. This is the main agent (1).

Production Example 2 Tetraglycidyldiaminodiphenylmethane [trade name Sumiepoxy ELM-434, manufactured by Sumitomo Chemical Co., Ltd.] 300
700 parts of a bisphenol A type epoxy resin [trade name Epicoat 828, manufactured by Yuka Shell Epoxy Co., Ltd.] was uniformly dissolved in a part to obtain a viscous liquid. This is the main agent (2).

Production Example 3 Tetraglycidyldiaminodiphenylmethane [trade name Sumiepoxy ELM-434, manufactured by Sumitomo Chemical Co., Ltd.] 380
620 parts of bisphenol A type epoxy resin [trade name: Epicoat 828, manufactured by Yuka Shell Epoxy Co., Ltd.] was uniformly dissolved in a part to obtain a viscous liquid. This is the main agent (3).

Production Example 4 Tetraglycidyldiaminodiphenylmethane [trade name Sumiepoxy ELM-434, manufactured by Sumitomo Chemical Co., Ltd.] is used as the main ingredient (4).

Production Example 5 Formalin condensate of aniline [trade name MDA-150,
Mitsui Toatsu Co., Ltd.] 207 parts and 700 parts of N-methylaniline formalin condensate (number average molecular weight 270) 700 parts were uniformly dissolved in polyoxytetramethylene glycol having a molecular weight of about 3,000 [trade name PTMG- 3000, manufactured by Sanyo Chemical Industry Co., Ltd.] Tolmol tolylene diisocyanate [trade name TDI-80, Nippon Polyurethane Co., Ltd.]
[Preparation] A viscous liquid was obtained by reacting 93 parts of a urethane prepolymer [this is an oligomer (1)] reacted with 1.5 mol. This is designated as a curing agent (1).

Production Example 6 Formalin condensate of aniline [trade name MDA-150,
Mitsui Toatsu Co., Ltd.] 207 parts and 700 parts of N-methylaniline formalin condensate (number average molecular weight 270) are uniformly dissolved to obtain a curing agent (2).

Production Example 7 To 100 parts of N-methylaniline formalin condensate (number average molecular weight of 270), a urethane prepolymer [trade name: Samprene P-663L, manufactured by Sanyo Chemical Industry Co., Ltd.] 20
The one obtained by reacting parts is used as a curing agent (3).

Production Example 8 Formalin condensate of aniline [trade name MDA-150,
Mitsui Toatsu Co., Ltd.] as the curing agent (4).

Example 1 65 parts of a curing agent (1) and an antifoaming agent [trade name Dappo SN-34 were added to 100 parts of a main agent (1) whose temperature was adjusted to 50 ° C., respectively.
8, manufactured by San Nopco Co., Ltd.] 0.1 part was uniformly mixed and defoamed under reduced pressure, and this was 10 mm × 120 mm × 120 m
m into the mold which has been subjected to a mold release treatment, cured at 80 ° C. for 4 hours, then released from the mold and further at 120 ° C. for 2 hours, 1
It was post-cured at 50 ° C. for 4 hours to obtain a plate-shaped surface layer-forming resin cured piece for a calendar roll.

Example 2 To 100 parts of the main agent (2), 60 parts of a curing agent (1) and an antifoaming agent [trade name: Dappo SN-348, San Nopco Ltd.
[Preparation] 0.1 part was used to obtain a plate-shaped surface layer-forming cured resin piece for a calendar roll according to Example 1.

Example 3 To 100 parts of the main agent (3), 62 parts of a curing agent (1) and an antifoaming agent [trade name: Dappo SN-348, San Nopco Ltd.
[Preparation] 0.1 part was used to obtain a plate-shaped surface layer-forming cured resin piece for a calendar roll according to Example 1.

Comparative Example 1 To 100 parts of the main agent (1), 59 parts of a curing agent (2) and an antifoaming agent [trade name: Dappo SN-348, San Nopco Ltd.
[Preparation] 0.1 part was used to obtain a plate-shaped surface layer-forming cured resin piece for a calendar roll according to Example 1.

Comparative Example 2 Based on 100 parts of the main agent (1), 34 parts of the curing agent (4) and an antifoaming agent [trade name: Dappo SN-348, San Nopco Ltd.
[Preparation] 0.1 part was used to obtain a plate-shaped surface layer-forming cured resin piece for a calendar roll according to Example 1.

Comparative Example 3 Using 1 part of the main agent (4), 112 parts of the curing agent (3) and 0.1 part of an antifoaming agent [trade name Dappo SN-348, manufactured by San Nopco Ltd.] were used. A plate-shaped surface layer-forming resin-hardened piece for a calendar roll was obtained in accordance with the procedure.

Using the surface layer forming resins for calender rolls of Examples 1 to 3 and Comparative Examples 1 to 3, the basic properties of the calender roll, namely compression recovery, hardness, heat resistance and impact strength, were measured. The results are shown in Table 1.

[0038]

[Table 1]

Compression set: In the Rockwell hardness test method for plastics specified in JIS K 7202, M scale, that is, a steel ball indenter having a diameter of 6.350 mm is used.
It is the amount represented by the penetration depth h of the indenter when the test is performed according to the above-mentioned test method with a reference load of 10 kgf and a test load of 100 kgf. Shore D hardness: as specified in ASTM D2240. Heat distortion temperature, impact strength: Also specified in JIS K 6911.

As is clear from Table 1, the surface layer forming resin for calender rolls according to this example has low hardness, high impact resistance and a small compression set, and has sufficient heat resistance when used as a calender roll. It turned out to have sex.

[0041]

The composition of the present invention is excellent in heat resistance and impact strength and has a low hardness, so that when it is run in contact with a metal roll, the material to be calendered such as paper and magnetic tape becomes smooth. It is possible to provide a surface layer-forming resin composition for a calendar roll which is excellent and has excellent durability because of its small compression set.

Claims (3)

[Claims] 1. A surface layer for a calendar roll comprising a liquid epoxy resin (A), an aromatic amine-based curing agent (B), and a reaction product (C) of an aromatic diamine (C1) and a urethane prepolymer (C2). Formable resin composition. 2. The aromatic amine curing agent (B) is aromatic 2
The composition according to claim 1, which comprises a primary amine curing agent. 3. The urethane prepolymer (C) is a polyoxytetramethylene glycol-based urethane prepolymer having a number average molecular weight of 3,000 to 30,000.
Or the composition according to 2.