Releasable adhesives for attachment of substrates and joints

• US 20020173582A1
• Filed: 02/07/2002
• Published: 11/21/2002
• Est. Priority Date: 11/24/1999
• Status: Abandoned Application

• Current Assignee: HELLA KG Hueck & Co.
• Original Assignee: HELLA KG Hueck & Co.
• Inventors: Schmidt, Stephan
• Application Number:
  US10/067,196
• Publication Number:
  US 20020173582A1
• Time in Patent Office: Days
• US Class Current: 524/504
• CPC Class Codes: B29C 65/4815 Hot melt adhesives, e.g. thermoplastic adhesives
• CPC Class Codes: B29C 65/76 Making non-permanent or releasable joints
• CPC Class Codes: B29C 66/1162 Single bevel to bevel joints, e.g. mitre joints
• CPC Class Codes: B29C 66/54 Joining several hollow-preforms, e.g. half-shells, to form hollow articles, e.g. for making balls, containers; Joining several hollow-preforms, e.g. half-cylinders, to form tubular articles
• CPC Class Codes: B29C 66/71 characterised by the composition of the plastics material of the parts to be joined welding bar compositions B29C65/125
• CPC Class Codes: B29C 66/7392 characterised by the material of at least one of the parts being a thermoplastic
• CPC Class Codes: B29C 66/7394 characterised by the material of at least one of the parts being a thermoset
• CPC Class Codes: B29K 2023/083 EVA, i.e. ethylene vinyl acetate copolymer
• CPC Class Codes: B29K 2023/12 PP, i.e. polypropylene
• CPC Class Codes: B29K 2033/12 Polymers of methacrylic acid esters, e.g. PMMA, i.e. polymethylmethacrylate
• CPC Class Codes: B29K 2069/00 Use of PC, i.e. polycarbonates or derivatives thereof, as moulding material
• CPC Class Codes: B29L 2031/3055 Cars
• CPC Class Codes: B29L 2031/747 Lightning equipment
• CPC Class Codes: C08F 255/00 Macromolecular compounds obtained by polymerising monomers on to polymers of hydrocarbons as defined in group C08F10/00
• CPC Class Codes: C08F 287/00 Macromolecular compounds obtained by polymerising monomers on to block polymers
• CPC Class Codes: C08L 2666/02 Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: C08L 2666/24 Graft or block copolymers according to groups C08L51/00, C08L53/00 or C08L55/02; Derivatives thereof
• CPC Class Codes: C09J 151/06 grafted on to homopolymers or copolymers of aliphatic hydrocarbons containing only one carbon-to-carbon double bond
• CPC Class Codes: C09J 153/02 Vinyl aromatic monomers and conjugated dienes
• CPC Class Codes: C09J 153/025 modified

Abstract

A Joint between a first and a second assembly part has adjoining side walls, which may be tightly joined together by means of a sealing bed provided with a removable adhesive sealant, The first side wall has a first sealing surface attached thereto, the first side wall in the joined state running at a distance approximately parallel to a second sealing surface attached to a second side wall, and both of the sealing surfaces form the sealing bed with a level running direction, directed away from the side walls, in whose extension the adhesive sealing material can be withdrawn. A method for producing a joint between a first assembly part and a second assembly part, where a removable adhesive sealant is applied in the liquid state to a sealing bed area of the first assembly part, and both of the assembly parts are joined together. To remove said adhesive sealant, the same is grasped at a free end and, in an extension of a level running direction of the sealing bed, directed away from both assembly parts, is withdrawn essentially residue-free from the sealing bed.

Claims

1. A hot-melt adhesive comprising a non-pressure-sensitive adhesive that is fluid at application temperatures and that is removable, residue-free, by peeling at small peel angles, wherein the improvement comprises that said adhesive contains additives selected from the group consisting of fillers, stabilizers, dyes, carbon black, and moisture absorbents, said adhesive also containing the following:

a) thermoplastic elastomers that may be grafted,

b) grafted poly-α

-olefins,

c) polyisobutylene or a softening oil,

d) adhesive resin, and

e) end block resin.

2. The adhesive according to claim 1, wherein the thermoplastic elastomers are styrenes selected from the group consisting of SBS, SIS, SEBS, SEPS, and block polystyrene-(block poly(ethylene-butylene)), block polystyrene-(block poly(ethylene-butylene)) having 1 to 10 block styrene units per molecule, which optionally are modified with block polyisoprene or block butadiene units;

elastomer alloys selected from the group consisting of EPDMIPP, NR/PP, EVA/PVDC, and NBR/PP, polyurethane, polyether esters, or polyamides.

3. The adhesive according to claim 1, wherein the poly-α

-olefins are at least partially grafted, and the poly-α

-olefins are selected from amorphous poly-α

-olefins, monopolymers, copolymers, or terpolymers of the monomers ethylene, propylene, 1-butene, 1-pentene, and 1-hexene, or from a poly-α

-olefin of the general formula (I);

4. The adhesive according to claim 3, wherein the poly-α

-olefins are semicrystalline, and the poly-α

-olefins comprise at least one of polyethylene, polypropylene, or poly-1-butene, which have high tacticity in the crystalline regions.

5. The adhesive according to claim 3 or 4, wherein the poly-α

-olefins are randomly grafted with olefinically unsaturated compounds, which in particular are selected from maleic anhydride, itaconic anhydride, tetrahydrophthalic anhydride, and compounds of the general formula (II);

6. An adhesive according to claim 1, wherein the quantity of grafted poly-α

-olefins is 0 to 100% by weight, relative to the total content of poly-α

-olefins.

7. The adhesive according to claim 1, wherein the thermoplastic elastomers are randomly grafted with olefinically unsaturated compounds that are selected from maleic anhydride, itaconic anhydride, tetrahydrophthalic anhydride, or compounds of the general formula (II):

8. The adhesive according to claim 1, wherein the percentage of grafted thermoplastic elastomers, relative to the total content of the thermoplastic elastomers, is 0 to 1 00% by weight.

9. The adhesive according to claim 1, wherein the adhesive resins are selected from polymeric monomers of the petrochemical C₅ to C₉ distillation fractions, which are not hydrated partially hydrated, or completely hydrated, natural rosin resins, modified natural rosin resins, terpene resins, polyterpene resins of β

-pinene, α

-pinene, and/or δ

-limonene;

resins obtained by copolymerization of terpene with monomers from the C₅ to C₉ fraction from petroleum distillation, or terpene-phenol resins.

10. The adhesive according to claim 1, wherein the polyisobutylenes are at least one selected from the group consisting of homopolymers of isobutylene of average molecular weight in the range of 20,000 to 5,000,000 g×

mol<sup>−

1</sup> (determined by gel permeation chromatography), copolymers of isobutylene and a conjugated diene in quantities of 0.3 to 4.5 mol % (relative to said copolymer), terpolymers of isobutylene, divinylbenzene in quantities of 0.01 to 4.5 mol %, and the named conjugated diene.

11. The adhesive according to claim 1, wherein the polyisobutylenes or softening oils are selected from polyisobutylenes, oligomers or polymers of isobutylene or 1-butene, or and modified naphthalene- or paraffin-based oils recovered from petroleum distillation with an average molecular weight in the range of 200 to 20,000 g×

mol^{31 1} (determined using gel permeation chromatography).

12. The adhesive according to claim 1, wherein said adhesive contains:

f) 0 to 80% by weight, preferably 15 to 70% by weight of polyisoprene, polybutadiene, grafted polyisoprene or polybutadiene.

13. The adhesive according to claim 1, wherein said adhesive contains:

g) 0 to 50% by weight, preferably 0 to 40% by weight, fillers; and

h) 0 to 25% by weight, preferably 0 to 10% by weight, aromatic resins and/or stabilizers.

14. The adhesive according to claim 13, wherein the fillers are inorganic fillers selected from the group consisting of calcium carbonate, calcium hydroxide, calcium oxide, dolomite, titanium dioxide, zinc oxide, silicon oxide, barium sulfate, manganese dioxide;

or the fillers are an organic filler which is preferably carbon black.

15. The adhesive according to claim 13, wherein the stabilizers are selected from the group consisting of epoxides, sterically hindered phenols, amines, thioesters, phosphites, and triazine-, piperidine-, and benzotriazoles.

16. The adhesive according to claim 1, wherein said adhesives contain adhesives comprising at least one of epoxy resins, silicones, polysulfides, polyurethanes, polyureas, or acrylates.