Melamine resin prepregs and melamine resin laminates based on modified melamine resins

• US 5,206,066 A
• Filed: 07/10/1992
• Issued: 04/27/1993
• Est. Priority Date: 08/05/1991
• Status: Expired due to Fees

• Current Assignee: Chemie LINZ GmbH
• Original Assignee: Chemie LINZ GmbH
• Inventors: Horacek, Heinrich
• Primary Examiner(s): Kight, III, John
• Assistant Examiner(s): ACQUAH, SAMUEL A
• Application Number:
  US07/911,931
• Time in Patent Office: 291 Days
• Field of Search: 528/230, 528/254, 528/272, 528/300, 528/302, 528/332, 525/437, 525/441, 525/472, 428/113, 428/175, 428/200, 428/224, 428/236, 428/268, 427/207.1, 427/331
• US Class Current: 428/113
• CPC Class Codes: C08G 12/427 Melamine
• CPC Class Codes: C08G 12/46 Block or graft polymers prepared by polycondensation of aldehydes or ketones on to macromolecular compounds
• CPC Class Codes: C08J 2361/28 with melamine
• CPC Class Codes: C08J 5/244 using glass fibres
• CPC Class Codes: Y10T 428/24124 Fibers
• CPC Class Codes: Y10T 428/24636 Embodying mechanically interengaged strand[s], strand-portion[s] or strand-like strip[s] [e.g., weave, knit, etc.]
• CPC Class Codes: Y10T 428/24843 with heat sealable or heat releasable adhesive layer
• CPC Class Codes: Y10T 442/2992 Coated or impregnated glass fiber fabric
• CPC Class Codes: Y10T 442/3569 Woven fabric layers impregnated with a thermosetting resin

Abstract

Melamine resin prepregs or melamine resin laminates which consist of a web-like fiber reinforcement which is impregnated with melamine resins which essentially comprise

a) 40-85% by weight of at least partly etherified melamine resins, which are obtainable by reaction of melamine, formaldehyde and alkanols having 1 to 8 C atoms in a molar ratio of melamine formaldehyde:alkanol of 1:(5 to 6):(4 to 6), and

b) 60-15% by weight of diols consisting of 25 to 75% by weight of polyester-diols and/or polyether-diols having a molecular weight of at least 400 g/mol and 75 to 25% by weight of low molecular weight diols having 2 to 12 C atoms.

Claims

1. Melamine resin prepregs or melamine resin laminates consisting of a web-like fiber reinforcement impregnated with at least partly etherified, modified melamine resins comprising

a) 40-85% by weight of at least partly etherified melamine resins, which are obtained by reaction of melamine, formaldehyde and alkanols having 1 to 8 C atoms in a molar ratio of melamine:

formaldehyde;

alkanol of 1;

(5 to

     6);

(4 to

     6), and

b) 60-15% by weight of diols consisting of 25 to 75% by weight of polyester-diols and/or polyether-diols having a molecular weight of at least 400 g/mol and 75 to 25% by weight of low molecular weight diols having 2 to 12 C atoms and a molecular weight of less than about 350 g/mol.

2. Melamine resin prepregs or melamine resin laminates according to claim 1, wherein the at least partly etherified, modified melamine resins comprising

a) 50 to 70% by weight of at least partly etherified melamine resins and

b) 50 to 30% by weight of diols.

3. Melamine resin prepregs or melamine resin laminates according to claim 1, wherein the alkanols have 1 to 4 C atoms.

4. Melamine resin prepregs or melamine resin laminates according to claim 1, wherein

the diols consist of 40 to 60% by weight of polyester-diols and/or polyether-diols and 60 to 40% by weight of low molecular weight diols.

5. Melamine resin prepregs or melamine resin laminates according to claim 1, wherein

the polyester-diols are condensation products of adipic acid and/or phthalic acid with ethylene glycol and/or 1,4-butanediol.

6. Melamine resin prepregs or melamine resin laminates according to claim 1, wherein

the polyether-diols are polytetrahydrofuran-diols.

7. Melamine resin prepregs or melamine resin laminates according to claim 1, wherein

the fiber reinforcement consists of a non-woven, woven fabric or fiber woven fabric of glass, carbon or aramid fibers.

8. Process for the production of melamine resin prepregs or melamine resin laminates, wherein

a web-like fiber reinforcement is impregnated with at least partly etherified, modified melamine resins comprising

a) 40-85% by weight of at least partly etherified melamine resins, which are obtainable by reaction of melamine, formaldehyde and alkanols having 1 to 8 C atoms in a molar ratio of melamine formaldehyde:

alkanol of 1;

(5 to

     6);

(4 to

     6), and

b) 60-15% by weight of diols consisting of 25 to 75% by weight of polyester-diols and/or polyether-diols having a molecular weight of at least 400 g/mol and 75 to 25% by weight of low molecular weight diols having 2 to 12 C atoms and a molecular weight of less than about 350 g/mol, and optionally,

the prepreg obtained during the impregnation is partly or completely cured.

9. Modified at least partly etherified melamine resins comprising

a) 40-85% by weight of at least partly etherified melamine resins, which are obtained by reaction of melamine, formaldehyde and alkanols having 1 to 8 C atoms in a molar ratio of melamine:

formaldehyde;

alkanol of 1;

(5 to

     6);

(4 to

     6), and

b) 60-15% by weight of diols consisting of 25 to 75% by weight of polyester-diols and/or polyether-diols having a molecular weight of at least 400 g/mol and 75 to 25% by weight of low molecular weight diols having 2 to 12 C atoms and a molecular weight of less than about 350 g/mol.